LeetCode59

src/main/java/cn/whaifree/leetCode/middle/LeetCode59.java

@@ -0,0 +1,74 @@
+package cn.whaifree.leetCode.middle;
+
+import org.junit.Test;
+
+/**
+ * 给你一个正整数 n ，生成一个包含 1 到 n2 所有元素，且元素按顺时针顺序螺旋排列的 n x n 正方形矩阵 matrix 。
+ *
+ *
+ *
+ * 示例 1：
+ *
+ *
+ * 输入：n = 3
+ * 输出：[[1,2,3],[8,9,4],[7,6,5]]
+ * 示例 2：
+ *
+ * 输入：n = 1
+ * 输出：[[1]]
+ *
+ *
+ * 提示：
+ *
+ * 1 <= n <= 20
+ */
+public class LeetCode59 {
+
+    public int[][] generateMatrix(int n) {
+        int cycle = 0; // 循环次数
+        int start = 0; //  本次循环的开始
+        int[][] ints = new int[n][n];
+        int fillNumber = 1;
+        int i, j;
+        while (cycle++ < n / 2) {
+            // 每个边填充数字
+            int path = n - cycle;
+            for (i = start; i < path; i++) {
+                ints[start][i]=fillNumber++;
+            }
+            for (j = start; j < path; j++) {
+                ints[j][i] = fillNumber++;
+            }
+            for (; i >= n - path; i--) {
+                ints[j][i] = fillNumber++;
+            }
+            for (; j >= n - path; j--) {
+                ints[j][i]=fillNumber++;
+            }
+            start++;
+        }
+        if (n % 2 == 1) {
+            ints[start][start] = fillNumber++;
+        }
+        return ints;
+    }
+
+    @Test
+    public void test() {
+        int[][] ints = generateMatrix(11);
+        for (int[] anInt : ints) {
+            for (int i : anInt) {
+                System.out.print(i+" ");
+            }
+            System.out.println();
+        }
+
+       /* [[1,2,3,4,5,6,7],
+        [24,25,26,27,28,29,8],
+        [23,40,41,42,43,30,9],
+        [22,39,48,49,44,31,10],
+        [21,38,47,46,45,32,11],
+        [20,37,36,35,34,33,12],
+        [19,18,17,16,15,14,13]]*/
+    }
+}