添加 0059.螺旋矩阵II.md C语言版本

problems/0059.螺旋矩阵II.md

@@ -468,6 +468,65 @@ class Solution {
 }
 ```
 
+C:
+```c
+int** generateMatrix(int n, int* returnSize, int** returnColumnSizes){
+    //初始化返回的结果数组的大小
+    *returnSize = n;
+    *returnColumnSizes = (int*)malloc(sizeof(int) * n);
+    //初始化返回结果数组ans
+    int** ans = (int**)malloc(sizeof(int*) * n);
+    int i;
+    for(i = 0; i < n; i++) {
+        ans[i] = (int*)malloc(sizeof(int) * n);
+        (*returnColumnSizes)[i] = n;
+    }
+
+    //设置每次循环的起始位置
+    int startX = 0;
+    int startY = 0;
+    //设置二维数组的中间值，若n为奇数。需要最后在中间填入数字
+    int mid = n / 2;
+    //循环圈数
+    int loop = n / 2;
+    //偏移数
+    int offset = 1;
+    //当前要添加的元素
+    int count = 1;
+
+    while(loop) {
+        int i = startX;
+        int j = startY;
+        //模拟上侧从左到右
+        for(; j < startY + n - offset; j++) {
+            ans[startX][j] = count++;
+        }
+        //模拟右侧从上到下
+        for(; i < startX + n - offset; i++) {
+            ans[i][j] = count++;
+        }
+        //模拟下侧从右到左
+        for(; j > startY; j--) {
+            ans[i][j] = count++;
+        }
+        //模拟左侧从下到上
+        for(; i > startX; i--) {
+            ans[i][j] = count++;
+        }
+        //偏移值每次加2
+        offset+=2;
+        //遍历起始位置每次+1
+        startX++;
+        startY++;
+        loop--;
+    }
+    //若n为奇数需要单独给矩阵中间赋值
+    if(n%2)
+        ans[mid][mid] = count;
+
+    return ans;
+}
+```
 
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 * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)