From a834a2f158236b0463b8cfa398515c67ccbe5001 Mon Sep 17 00:00:00 2001 From: whai Date: Tue, 12 Mar 2024 19:10:07 +0800 Subject: [PATCH] =?UTF-8?q?=E5=8A=A8=E6=80=81=E8=A7=84=E5=88=92=20?= =?UTF-8?q?=E8=83=8C=E5=8C=85=E9=97=AE=E9=A2=98?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../leetCode/BackTracking/LeetCode17.java | 2 +- .../cn/whaifree/leetCode/Dynamic/BeiBao.java | 84 +++++++++++ .../leetCode/Dynamic/LeetCode343.java | 47 ++++++ .../whaifree/leetCode/Dynamic/LeetCode63.java | 57 ++++++++ .../whaifree/leetCode/Dynamic/LeetCode96.java | 64 ++++++++ .../whaifree/leetCode/Greedy/LeetCode122.java | 70 +++++++++ .../whaifree/leetCode/Greedy/LeetCode322.java | 44 ------ .../whaifree/leetCode/Greedy/LeetCode53.java | 38 ++++- src/main/java/cn/whaifree/leetCode/Tes1.java | 34 +++++ .../redo/redo_24_3_9/LeetCode134.java | 59 ++++++++ .../redo/redo_24_3_9/LeetCode236.java | 46 ++++++ .../redo/redo_24_3_9/LeetCode376.java | 34 +++++ .../redo/redo_24_3_9/LeetCode435.java | 78 ++++++++++ .../whaifree/redo/redo_24_3_9/LeetCode45.java | 45 ++++++ .../redo/redo_24_3_9/LeetCode450.java | 54 +++++++ .../redo/redo_24_3_9/LeetCode452.java | 54 +++++++ .../redo/redo_24_3_9/LeetCode509.java | 40 +++++ .../redo/redo_24_3_9/LeetCode738.java | 44 ++++++ .../redo/redo_24_3_9/LeetCode763.java | 49 +++++++ .../redo/redo_24_3_9/LeetCode968.java | 68 +++++++++ src/test/java/TestInteger.java | 138 ++++++++++++++++++ 21 files changed, 1103 insertions(+), 46 deletions(-) create mode 100644 src/main/java/cn/whaifree/leetCode/Dynamic/BeiBao.java create mode 100644 src/main/java/cn/whaifree/leetCode/Dynamic/LeetCode343.java create mode 100644 src/main/java/cn/whaifree/leetCode/Dynamic/LeetCode63.java create mode 100644 src/main/java/cn/whaifree/leetCode/Dynamic/LeetCode96.java create mode 100644 src/main/java/cn/whaifree/leetCode/Greedy/LeetCode122.java delete mode 100644 src/main/java/cn/whaifree/leetCode/Greedy/LeetCode322.java create mode 100644 src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode134.java create mode 100644 src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode236.java create mode 100644 src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode376.java create mode 100644 src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode435.java create mode 100644 src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode45.java create mode 100644 src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode450.java create mode 100644 src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode452.java create mode 100644 src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode509.java create mode 100644 src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode738.java create mode 100644 src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode763.java create mode 100644 src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode968.java create mode 100644 src/test/java/TestInteger.java diff --git a/src/main/java/cn/whaifree/leetCode/BackTracking/LeetCode17.java b/src/main/java/cn/whaifree/leetCode/BackTracking/LeetCode17.java index 8650adc..c829ace 100644 --- a/src/main/java/cn/whaifree/leetCode/BackTracking/LeetCode17.java +++ b/src/main/java/cn/whaifree/leetCode/BackTracking/LeetCode17.java @@ -16,7 +16,7 @@ public class LeetCode17 { @Test public void test() { String digits = "23"; - new Solution1().letterCombinations(digits).forEach(s -> System.out.println(s)); + new Solution().letterCombinations(digits).forEach(s -> System.out.println(s)); } class Solution { diff --git a/src/main/java/cn/whaifree/leetCode/Dynamic/BeiBao.java b/src/main/java/cn/whaifree/leetCode/Dynamic/BeiBao.java new file mode 100644 index 0000000..e41576f --- /dev/null +++ b/src/main/java/cn/whaifree/leetCode/Dynamic/BeiBao.java @@ -0,0 +1,84 @@ +package cn.whaifree.leetCode.Dynamic; + +import org.junit.Test; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/3/12 16:53 + * @注释 + */ +public class BeiBao { + + @Test + public void main() { + int[] weight = {1,3,4}; + int[] value = {15,20,30}; + int bagSize = 4; + new Solution().packageProblem(weight, value, bagSize); + } + + class Solution{ + + /** + * + * + *
+ * + * + * @param weights 每个物品的重量 + * @param values 每个物品的价值 + * @param carryNumber 允许携带的数量 + * @return 价值 + */ + public int packageProblem(int[] weights, int[] values, int carryNumber) { + /** + * 重量 价值 + * 物品0 1 15 + * 物品1 3 20 + * 物品2 4 30 + */ + // dp[i][j] i表示携带的产品，j表示容量为j的背包 dp[i][j]为从0-i个产品里取，最大的价值 + // 1. 不放物品i的最大价值，dp[i][j] = dp[i-1][j] 不放物品i，所以i不占重量，所以不用-weight[i] + // 2. 放物品i的最大价值 dp[i-1][j-weight[i]] + value[i] 如果放了物品i，那最大价值就 不放物品i的最大价值+物品i的价值（j-weight[i] 表示放i需要腾出来空间） + // dp[i - 1][j - weight[i]] 为背包容量为j - weight[i]的时候不放物品i的最大价值，注意是不放物品i，所以要减去weight[i] + // dp[i][j] = max(dp[i - 1][j], dp[i - 1][j - weight[i]] + value[i]); 不放物品的价值 加上i物品的价值 + + // 初始化：如果容量为0，最大价值都为0；如果容量为1、2、3，只能放物品0的时候，最大价值都是15 + int goodsNumber = weights.length; + int[][] dp = new int[goodsNumber][carryNumber + 1]; + // 把第0个物品进行初始化，前提是能够放入第0个物品 + for (int i = weights[0]; i < carryNumber + 1; i++) { + dp[0][i] = values[0]; + } + + /** + * 先遍历物品，再遍历背包 + */ + for (int i = 1; i < goodsNumber; i++) { + for (int j = 1; j < carryNumber + 1; j++) { + if (weights[i] > j) { + // 物品i放不进背包容量为j的背包 + dp[i][j] = dp[i - 1][j]; + }else { + // 能放进去 + dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - weights[i]] + values[i]); + } + } + } + + + + // 打印dp数组 + for (int i = 0; i < goodsNumber; i++) { + for (int j = 0; j <= carryNumber; j++) { + System.out.print(dp[i][j] + "\t"); + } + System.out.println("\n"); + } + + return dp[weights.length - 1][carryNumber]; + } + + } +} diff --git a/src/main/java/cn/whaifree/leetCode/Dynamic/LeetCode343.java b/src/main/java/cn/whaifree/leetCode/Dynamic/LeetCode343.java new file mode 100644 index 0000000..6b28608 --- /dev/null +++ b/src/main/java/cn/whaifree/leetCode/Dynamic/LeetCode343.java @@ -0,0 +1,47 @@ +package cn.whaifree.leetCode.Dynamic; + +import org.junit.Test; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/3/11 11:14 + * @注释 + */ +public class LeetCode343 { + + @Test + public void test() { + System.out.println(new Solution().integerBreak(10)); + } + + class Solution { + /** + * dp[i] 表示 拆分出i后的乘积的最大值 + * dp[i] = 遍历 dp[i-j] * i 或者 i * j + * dp[i] 可能为两个数相乘，或者是多个数相乘（这时就需要遍历）。 + * 初始化 dp[0] = null；dp[1] = 1; + * + * [0 1 2 3 4 5 6 7 8 9 10] + * [1 1 1 2 4 6 9 12 16 27 36] + * + * + * @param n + * @return + */ + public int integerBreak(int n) { + + int[] dp = new int[n + 1]; +// dp[0] = 1; + dp[2] = 1; // 表示数字2可以划分为1+1 1*1为最大值 + for (int i = 2; i < n+1; i++) { + for (int j = 1; j < i - 1; j++) { + // Math.max((i - j) * j, dp[i - j] * j) 表示两个数相乘 和使用 前面的数相乘 + dp[i] = Math.max(dp[i], Math.max((i - j) * j, dp[i - j] * j)); + } + } + + return dp[n]; + } + } +} diff --git a/src/main/java/cn/whaifree/leetCode/Dynamic/LeetCode63.java b/src/main/java/cn/whaifree/leetCode/Dynamic/LeetCode63.java new file mode 100644 index 0000000..3ea22b0 --- /dev/null +++ b/src/main/java/cn/whaifree/leetCode/Dynamic/LeetCode63.java @@ -0,0 +1,57 @@ +package cn.whaifree.leetCode.Dynamic; + +import org.junit.Test; + +import java.util.Arrays; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/3/9 12:04 + * @注释 + */ +public class LeetCode63 { + + @Test + public void test() { + int[][] ints = new int[][]{{0,0,0,0},{0,1,0,0},{0,0,0,0}}; + System.out.println(new Solution().uniquePathsWithObstacles(ints)); + } + + class Solution { + /** + * dp[i][j] 表示 i,j出可能的路径 + * dp[i][j] = dp[i-1][j] + dp[i][j-1] 且如果该点有障碍，直接continue + * 初始化 dp【0,0】=0 + * @param obstacleGrid + * @return + */ + public int uniquePathsWithObstacles(int[][] obstacleGrid) { + + if (obstacleGrid[0][0] == 1) { + return 0;//起点就有障碍，不可能过去 + } + + int h = obstacleGrid.length; + int w = obstacleGrid[0].length; + int[][] dp = new int[h][w]; + dp[0][0] = 1; + for (int i = 0; i < dp.length; i++) { + for (int j = 0; j < dp[i].length; j++) { + if (i == 0 && j == 0) { + continue; + } + + if (obstacleGrid[i][j] == 0) { + int tmp = 0; + if (i >= 1) tmp += dp[i - 1][j]; + if (j >= 1) tmp += dp[i][j - 1]; + dp[i][j] = tmp; + } + } + } + + return dp[h-1][w-1]; + } + } +} diff --git a/src/main/java/cn/whaifree/leetCode/Dynamic/LeetCode96.java b/src/main/java/cn/whaifree/leetCode/Dynamic/LeetCode96.java new file mode 100644 index 0000000..320b890 --- /dev/null +++ b/src/main/java/cn/whaifree/leetCode/Dynamic/LeetCode96.java @@ -0,0 +1,64 @@ +package cn.whaifree.leetCode.Dynamic; + +import org.junit.Test; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/3/11 13:08 + * @注释 + */ +public class LeetCode96 { + + @Test + public void test() { + int n = 5; + int result = new Solution().numTrees(n); + System.out.println(result); + } + + class Solution { + + /** + * + * dp[i] 表示有两个节点的可能数 + * + * 以n=3举例，二叉搜索树 + * 可能的方案： + * i表示以i为头节点 + * 1. 以1为头结点 右边2个子树+左边0个子树 + * 2. 以2为头节点 右边1个子树+左边1个子树 + * 3. 以3为头节点 右边0个子树+左边2个子树 + * + * dp[3] = 以1为头 dp[2] * dp[0] + + * 以2为头 dp[1] * dp[1] + + * 以3为头 dp[0] * dp[2] + * + * dp[i] = dp[i-1] * dp[0] + + * dp[i-2] * dp[1] + + * dp[i-3] * dp[02] + + * .... + * dp[0] * dp[i-1] + * @param n + * @return + */ + public int numTrees(int n) { + + if (n <= 1) { + return 1; + } + + int[] dp = new int[n + 1]; + dp[0] = 1; + dp[1] = 1; + dp[2] = 2; + for (int i = 3; i <= n; i++) { + for (int j = 1; j <= i; j++) { + dp[i] += (dp[i - j] * dp[j - 1]); + } + } + + return dp[n]; + } + } +} diff --git a/src/main/java/cn/whaifree/leetCode/Greedy/LeetCode122.java b/src/main/java/cn/whaifree/leetCode/Greedy/LeetCode122.java new file mode 100644 index 0000000..9f508ed --- /dev/null +++ b/src/main/java/cn/whaifree/leetCode/Greedy/LeetCode122.java @@ -0,0 +1,70 @@ +package cn.whaifree.leetCode.Greedy; + +import org.junit.Test; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/2/25 22:21 + * @注释 + */ +public class LeetCode122 { + + + @Test + public void test() { + + System.out.println(new Solution1().maxProfit(new int[]{7, 1, 5, 3, 6, 4})); + + System.out.println(new Solution1().maxProfit(new int[]{1})); + + + } + + class Solution { + + + /** + * 随时可以买卖，那么只要有跌的我都不要。 + * 上帝视角：只要涨我就全要 + * + * 7跌 1涨5 跌 4涨6 跌4 + * + * @param prices + * @return + */ + public int maxProfit(int[] prices) { + + int maxProfit = 0; + for (int i = 0; i < prices.length; i++) { + if (i > 0 && prices[i] - prices[i - 1] > 0) { + maxProfit += prices[i] - prices[i - 1]; + } + } + return maxProfit; + } + + } + + class Solution1 { + + /** + * dp[i] 表示当天可获得的收益 + * dp[i] = dp[i-1] + if(prices[i-1] < price[i]){prices[i] - price[i-1]} + * + * @param prices + * @return + */ + public int maxProfit(int[] prices) { + int[] dp = new int[prices.length]; + for (int i = 1; i < prices.length; i++) { + dp[i] = dp[i - 1]; + if (prices[i - 1] < prices[i]) { + // 挣钱 + dp[i] += prices[i] - prices[i - 1]; + } + } + return dp[prices.length - 1]; + } + } +} diff --git a/src/main/java/cn/whaifree/leetCode/Greedy/LeetCode322.java b/src/main/java/cn/whaifree/leetCode/Greedy/LeetCode322.java deleted file mode 100644 index fac8054..0000000 --- a/src/main/java/cn/whaifree/leetCode/Greedy/LeetCode322.java +++ /dev/null @@ -1,44 +0,0 @@ -package cn.whaifree.leetCode.Greedy; - -import org.junit.Test; - -/** - * @version 1.0 - * @Author whai文海 - * @Date 2024/2/25 22:21 - * @注释 - */ -public class LeetCode322 { - - - @Test - public void test() { - System.out.println(new Solution().maxProfit(new int[]{7, 1, 5, 3, 6, 4})); - } - - class Solution { - - - /** - * 随时可以买卖，那么只要有跌的我都不要。 - * 上帝视角：只要涨我就全要 - * - * 7跌 1涨5 跌 4涨6 跌4 - * - * @param prices - * @return - */ - public int maxProfit(int[] prices) { - - int maxProfit = 0; - for (int i = 0; i < prices.length; i++) { - if (i > 0 && prices[i] - prices[i - 1] > 0) { - maxProfit += prices[i] - prices[i - 1]; - } - } - return maxProfit; - } - - // TODO 动态规划 - } -} diff --git a/src/main/java/cn/whaifree/leetCode/Greedy/LeetCode53.java b/src/main/java/cn/whaifree/leetCode/Greedy/LeetCode53.java index f56bd66..ab2fdca 100644 --- a/src/main/java/cn/whaifree/leetCode/Greedy/LeetCode53.java +++ b/src/main/java/cn/whaifree/leetCode/Greedy/LeetCode53.java @@ -16,7 +16,9 @@ import java.util.concurrent.locks.ReentrantLock; public class LeetCode53 { @Test public void test() { - System.out.println(new LeetCode53().new Solution().maxSubArray(new int[]{-2, 1, -3, 4, -1, 2, 1, -5, 4})); + System.out.println(new Solution1().maxSubArray(new int[]{-2, 1, -3, 4, -1, 2, 1, -5, 4})); + System.out.println(new Solution1().maxSubArray(new int[]{5,4,-1,7,8})); + } class Solution { @@ -44,5 +46,39 @@ public class LeetCode53 { } + class Solution1 { + + /** + * 动态规化 + * dp[i] 表示i出最大子序列的和 + * if dp[i-1]+nums[i]>0 dp[i] = dp[i-1] + nums[i] + * else dp[i] = nums[i] + * + * [-2,1,-3,4,-1,2,1,-5,4] + * [-2,1,-3,4,3,5,6,1,5] + * + * @param nums + * @return + */ + public int maxSubArray(int[] nums) { + int[] dp = new int[nums.length]; + dp[0] = nums[0]; + int max = dp[0]; + for (int i = 1; i < nums.length; i++) { + dp[i] = Math.max(nums[i], dp[i - 1] + nums[i]); + max = Math.max(dp[i], max); +// if (dp[i - 1] > 0 && dp[i - 1] + nums[i] > 0) { +// dp[i] = dp[i - 1] + nums[i]; +// } else { +// dp[i] = nums[i]; +// } +// max = Math.max(dp[i], max); + } + return max; + + } + } + + } diff --git a/src/main/java/cn/whaifree/leetCode/Tes1.java b/src/main/java/cn/whaifree/leetCode/Tes1.java index 4725439..5ac9bff 100644 --- a/src/main/java/cn/whaifree/leetCode/Tes1.java +++ b/src/main/java/cn/whaifree/leetCode/Tes1.java @@ -108,6 +108,9 @@ public class Tes1 { } + private static final Object lock = new Object(); + private static int count = 0; + public static void main(String[] args) { // 创建一个TreeNode对象并创建其对应的PhantomReference和ReferenceQueue TreeNode treeNode = new TreeNode(11); @@ -130,6 +133,37 @@ public class Tes1 { } else { System.out.println("TreeNode对象还未被垃圾回收器回收"); } + + Thread t1 = new Thread(() -> { + synchronized (lock) { + while (count < 10) { + System.out.println("Thread 1: " + count++); + lock.notify(); + } + try { + lock.wait(); + } catch (InterruptedException e) { + throw new RuntimeException(e); + } + } + }); + + Thread t2 = new Thread(() -> { + synchronized (lock) { + while (count < 20) { + System.out.println("Thread 2: " + count++); + lock.notify(); + } + try { + lock.wait(); + } catch (InterruptedException e) { + throw new RuntimeException(e); + } + } + }); + + t1.start(); + t2.start(); } } diff --git a/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode134.java b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode134.java new file mode 100644 index 0000000..4aa1a7c --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode134.java @@ -0,0 +1,59 @@ +package cn.whaifree.redo.redo_24_3_9; + +import org.junit.Test; + +import java.util.Arrays; +import java.util.HashSet; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/3/10 12:32 + * @注释 + */ +public class LeetCode134 { + + @Test + public void test() { + int[] gas = {5,1,2,3,4}; + int[] cost = {4,4,1,5,1}; + int result = new Solution().canCompleteCircuit(gas, cost); + System.out.println(result); + } + + class Solution { + /** + * + * @param gas + * @param cost + * @return + */ + public int canCompleteCircuit(int[] gas, int[] cost) { + + //判断是否一定能绕圈 + int sumGas = 0; + for (int i : gas) { + sumGas += i; + } + int sumCost = 0; + for (int i : cost) { + sumCost += i; + } + if (sumGas= 0) || (curSub > 0 && preSub <= 0)) { + preSub = curSub; + res++; + } + } + return res; + + } + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode435.java b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode435.java new file mode 100644 index 0000000..1cb8c52 --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode435.java @@ -0,0 +1,78 @@ +package cn.whaifree.redo.redo_24_3_9; + +import org.junit.Test; + +import java.util.Arrays; +import java.util.Comparator; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/3/9 12:25 + * @注释 + */ +public class LeetCode435 { + + @Test + public void test() { + // [[1,2],[2,3],[3,4],[1,3]] +// int[][] intervals = new int[][]{{1, 2}, {2, 3}, {3, 4}, {1, 3}}; + int[][] intervals = new int[][]{{1, 4}, {3, 6}, {7, 10},{5, 8}, {9, 12}}; + + // [ [1,2], [1,2], [1,2] ] +// int[][] intervals = new int[][]{{1, 2}, {1, 2}, {1, 2}}; + System.out.println(new Solution1().eraseOverlapIntervals(intervals)); + } + + class Solution { + public int eraseOverlapIntervals(int[][] intervals) { + // 按照起始位置从小到大排序 + Arrays.sort(intervals, new Comparator() { + @Override + public int compare(int[] o1, int[] o2) { + return o1[0] - o2[0]; + } + }); + + // 如果i的起始位置比i-1的终点位置要小，那么就需要移除，并更新结束位置为min（last,last） + // 如果起始位置比i-1大，那么直接进入下个区间，并count++ + + int normalCount = 1; + for (int i = 1; i < intervals.length; i++) { + if (intervals[i][0] < intervals[i - 1][1]) { + // 需要去掉 + intervals[i][1] = Math.min(intervals[i][1], intervals[i - 1][1]); + }else { + normalCount++; + } + } + return intervals.length - normalCount; + + } + } + + class Solution1 { + public int eraseOverlapIntervals(int[][] intervals) { + // 按照起始位置从小到大排序 + Arrays.sort(intervals, new Comparator() { + @Override + public int compare(int[] o1, int[] o2) { + return o1[1] - o2[1]; + } + }); + + int right = intervals[0][1]; + int count = 1; + for (int i = 1; i < intervals.length; i++) { + if (intervals[i][0] < right) { + // 需要去掉 +// right = right; + }else { + right = intervals[i][1]; + count++; + } + } + return intervals.length - count; + } + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode45.java b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode45.java new file mode 100644 index 0000000..625e811 --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode45.java @@ -0,0 +1,45 @@ +package cn.whaifree.redo.redo_24_3_9; + +import org.junit.Test; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/3/10 12:12 + * @注释 + */ +public class LeetCode45 { + + @Test + public void test() { + int[] nums = {2, 3, 1, 1, 4}; + int jump = new Solution().jump(nums); + System.out.println(jump); + } + + class Solution { + public int jump(int[] nums) { + if (nums.length == 1) { + return 0; + } + // 在最大覆盖范围内向前 + int maxCover = 0; + int curCover = 0; + int jumpCount = 0; + for (int i = 0; i < nums.length; i++) { + maxCover = Math.max(maxCover, i + nums[i]); + if (i == curCover) { + jumpCount++; + curCover = maxCover; + // 必须等待区间增加后再判断是否到末位 + if (maxCover >= nums.length - 1) { + break; + } + } + } + return jumpCount; + + + } + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode450.java b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode450.java new file mode 100644 index 0000000..377da5b --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode450.java @@ -0,0 +1,54 @@ +package cn.whaifree.redo.redo_24_3_9; + +import cn.whaifree.leetCode.model.TreeNode; +import org.junit.Test; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/3/10 19:17 + * @注释 + */ +public class LeetCode450 { + + @Test + public void test() { + new Solution().deleteNode(TreeNode.constructTreeByArray(), 5).printTree(); + } + + class Solution { + public TreeNode deleteNode(TreeNode root, int key) { + if (root == null) { + return null; + } + return circle(root, key); + } + + public TreeNode circle(TreeNode root,int key) { + if (root == null) { + return null; + } + + if (root.val == key) { + // 将root.left全部移动到root.right.left.left.... + TreeNode index = root.right; + // 如果右边没有节点，直接返回左边的 + if (index == null) { + return root.left; + } + while (index.left != null) { + index = index.left; + } + index.left = root.left; + return root.right; + } + + if (root.val < key) { + root.right = circle(root.right, key); + }else { + root.left = circle(root.left, key); + } + return root; + } + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode452.java b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode452.java new file mode 100644 index 0000000..019efa1 --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode452.java @@ -0,0 +1,54 @@ +package cn.whaifree.redo.redo_24_3_9; + +import org.junit.Test; + +import java.util.Arrays; +import java.util.Comparator; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/3/9 13:22 + * @注释 + */ +public class LeetCode452 { + + @Test + public void test() + { + int[][] points = {{10,16},{2,8},{1,6},{7,12}}; + int[][] points1 = {{1, 2}, {3, 4}, {5, 6},{7,8}}; + int[][] points2 = {{1,2},{2,3},{3,4},{4,5}}; + System.out.println(new Solution().findMinArrowShots(points2)); + } + + + class Solution { + /** + * [[-2147483646,-2147483645],[2147483646,2147483647]] + * @param points + * @return + */ + public int findMinArrowShots(int[][] points) { + Arrays.sort(points, new Comparator() { + @Override + public int compare(int[] o1, int[] o2) { + if (o1[1] 0; i--) { + if (c[i] < c[i - 1]) { + // 注意一定要在这对c[i]--,668841 等第二个8变成了7，就又不是递增了，所以不能简单地找到前后两个递减就结束 + c[i - 1]--; + target = i; + } + } + + + for (int i = target; i < c.length; i++) { + c[i] = '9'; + } + + + + return Integer.valueOf(new String(c)); + } + } + +} diff --git a/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode763.java b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode763.java new file mode 100644 index 0000000..28ea623 --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode763.java @@ -0,0 +1,49 @@ +package cn.whaifree.redo.redo_24_3_9; + +import org.junit.Test; + +import java.util.ArrayList; +import java.util.List; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/3/9 13:38 + * @注释 + */ +public class LeetCode763 { + + @Test + public void test() { + new Solution().partitionLabels("ababcbacadefegdehijhklij").forEach( + i -> System.out.println(i) + ); + } + + class Solution { + public List partitionLabels(String s) { + + List res = new ArrayList<>(); + int[] map = new int[26]; + + // 计算最晚出现的索引 + // 如果当前i==最晚出现的索引，需要划分一次 + char[] chars = s.toCharArray(); + for (int i = 0; i < chars.length; i++) { + map[chars[i] - 'a'] = i; + } + + int left = -1; + int far = 0; + for (int i = 0; i < chars.length; i++) { + // 遍历的过程中，找到前面区间的最远边界 + far = Math.max(far, map[chars[i] - 'a']); + if (i == far) { + res.add(i - left); + left = i; + } + } + return res; + } + } +} diff --git a/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode968.java b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode968.java new file mode 100644 index 0000000..1b1c8fe --- /dev/null +++ b/src/main/java/cn/whaifree/redo/redo_24_3_9/LeetCode968.java @@ -0,0 +1,68 @@ +package cn.whaifree.redo.redo_24_3_9; + +import cn.whaifree.leetCode.model.TreeNode; +import org.junit.Test; + +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/3/10 11:35 + * @注释 + */ +public class LeetCode968 { + + @Test + public void test() { + System.out.println(new Solution().minCameraCover(TreeNode.constructTreeByArray(1,2,null,3,4,5,null,null,6))); + } + + class Solution { + int total = 0; + /** + * 监控二叉树 + * 2 被覆盖 + * 0 没覆盖 + * 1 有摄像头 + * + * 0 0 | 0 1 | 1 1 | 0 2 | 1 2 | 2 2 + * + * + * 根节点必然只能被监控，根节点的父节点放摄像头 + * @param root + * @return + */ + public int minCameraCover(TreeNode root) { + // 判断根节点的左右 + int rootIndex = Tracking(root); + if (rootIndex == 0) { + total++; + } + return total; + } + + public int Tracking(TreeNode root) { + if (root == null) { + return 2; // 空节点表示被覆盖 + } + + int left = Tracking(root.left); + int right = Tracking(root.right); + + if (left == 2 && right == 2) { + return 0; + } + // 如果左右存在没被覆盖的，这个点就放置一个摄像头 + if (left == 0 || right == 0) { + total++; + return 1; + } + // 如果左右子节点有摄像头，本节点为被覆盖的 + if (left ==1 || right == 1) { + return 2; + } + + return -1; + } + } + +} diff --git a/src/test/java/TestInteger.java b/src/test/java/TestInteger.java new file mode 100644 index 0000000..bbcdd65 --- /dev/null +++ b/src/test/java/TestInteger.java @@ -0,0 +1,138 @@ +/** + * @version 1.0 + * @Author whai文海 + * @Date 2024/3/10 12:49 + * @注释 + */ +public class TestInteger { + + public static void main(String[] args) { + Integer a = new Integer(100); + Integer b = new Integer(100); + System.out.println(a == b); //false 两个对象，指向 + + /** + * 0 new #2 + * 3 dup + * 4 bipush 100 + * 6 invokespecial #3 : (I)V> + * 9 astore_1 + * 10 new #2 + * 13 dup + * 14 bipush 100 + * 16 invokespecial #3 : (I)V> + * 19 astore_2 + * 20 getstatic #4 + * 23 aload_1 + * 24 aload_2 + * 25 if_acmpne 32 (+7) + * 28 iconst_1 + * 29 goto 33 (+4) + * 32 iconst_0 + * 33 invokevirtual #5 + */ + + + Integer c = new Integer(100); + int d = 100; + System.out.println(c == d); //true + /** + * 36 new #2 + * 39 dup + * 40 bipush 100 + * 42 invokespecial #3 : (I)V> + * 45 astore_3 + * 46 bipush 100 + * 48 istore 4 + * 50 getstatic #4 + * 53 aload_3 + * 54 invokevirtual #6 // Integer自动拆箱为int + * 57 iload 4 + * 59 if_icmpne 66 (+7) + * 62 iconst_1 + * 63 goto 67 (+4) + * 66 iconst_0 + * 67 invokevirtual #5 + */ + + + Integer e = new Integer(100); + Integer f = 100; + System.out.println(e == f); //false + /** + * 70 new #2 + * 73 dup + * 74 bipush 100 + * 76 invokespecial #3 : (I)V> + * 79 astore 5 + * 81 bipush 100 + * 83 invokestatic #7 //自动装箱，之后其实是一个new Integer(100) + * 86 astore 6 + * 88 getstatic #4 + * 91 aload 5 + * 93 aload 6 + * 95 if_acmpne 102 (+7) + * 98 iconst_1 + * 99 goto 103 (+4) + * 102 iconst_0 + * 103 invokevirtual #5 + */ + + Integer g = 100; // Integer i = Integer.valueOf(100) -128-127 会缓存，如果超过这个范围就是new Integer + Integer h = 100; // Integer i = Integer.valueOf(100) + System.out.println(g == h); //true + /** + * 106 bipush 100 + * 108 invokestatic #7 + * 111 astore 7 + * 113 bipush 100 + * 115 invokestatic #7 + * 118 astore 8 + * 120 getstatic #4 + * 123 aload 7 + * 125 aload 8 + * 127 if_acmpne 134 (+7) + * 130 iconst_1 + * 131 goto 135 (+4) + * 134 iconst_0 + * 135 invokevirtual #5 + */ + // java API中对Integer类型的valueOf的定义如下，对于-128到127之间的数，会进行缓存 + // sipush指令用于加载-32768到32767之间的整数常量到操作数栈中，而bipush指令则用于加载-128到127之间的整数常量到操作数栈中 + Integer j = 128; + Integer i = 128; + System.out.println(i == j); //false + /** + * 138 sipush 128 + * 141 invokestatic #7 + * 144 astore 9 + * 146 sipush 128 + * 149 invokestatic #7 + * 152 astore 10 + * 154 getstatic #4 + * 157 aload 10 + * 159 aload 9 + * 161 if_acmpne 168 (+7) + * 164 iconst_1 + * 165 goto 169 (+4) + * 168 iconst_0 + * 169 invokevirtual #5 + * 172 return + */ + } +} + + +class gg { + private static final int _1MB = 1024 * 1024; + public static void testAllocation() { + byte [] allocation1, allocation2, allocation3, allocation4; + allocation1 = new byte[2 *_1MB]; + allocation2 = new byte[2 *_1MB]; + allocation3 = new byte[2 *_1MB]; + allocation4 = new byte[4 *_1MB]; + } + public static void main(String[] args) { + testAllocation(); + } +}