Update README.md

Author: yanglbme

solution/0000-0099/0015.3Sum/README.md

@@ -455,59 +455,50 @@ class Solution {
 
 #### C
 
-```C
-
-int cmp(const void *a, const void *b) { return *(int *)a - *(int *)b; }
-
-int **threeSum(int *nums, int numsSize, int *returnSize,
-               int **returnColumnSizes) {
-  *returnSize = 0;
-  int capacity = 100;
-  int **result = malloc(capacity * sizeof(int *));
-  int *colSizes = malloc(capacity * sizeof(int));
-  qsort(nums, numsSize, sizeof(int), cmp);
-
-  for (int i = 0; i < numsSize - 2; i++) {
-    if (nums[i] > 0)
-      break;
-    if (i > 0 && nums[i] == nums[i - 1])
-      continue;
-
-    int j = i + 1, k = numsSize - 1;
-    while (j < k) {
-      int sum = nums[i] + nums[j] + nums[k];
-      if (sum < 0) {
-        j++;
-      } else if (sum > 0) {
-        k--;
-      } else {
-        if (*returnSize >= capacity) {
-          capacity *= 2;
-          result = realloc(result, capacity * sizeof(int *));
-          colSizes = realloc(colSizes, capacity * sizeof(int));
-        }
+```c
+int cmp(const void* a, const void* b) {
+    return *(int*) a - *(int*) b;
+}
 
-        result[*returnSize] = malloc(3 * sizeof(int));
-        result[*returnSize][0] = nums[i];
-        result[*returnSize][1] = nums[j];
-        result[*returnSize][2] = nums[k];
-        colSizes[*returnSize] = 3;
-        (*returnSize)++;
-
-        j++;
-        k--;
-        while (j < k && nums[j] == nums[j - 1])
-          j++;
-        while (j < k && nums[k] == nums[k + 1])
-          k--;
-      }
-    }
-  }
+int** threeSum(int* nums, int numsSize, int* returnSize, int** returnColumnSizes) {
+    *returnSize = 0;
+    int cap = 1000;
+    int** ans = (int**) malloc(sizeof(int*) * cap);
+    *returnColumnSizes = (int*) malloc(sizeof(int) * cap);
 
-  *returnColumnSizes = colSizes;
-  return result;
-}
+    qsort(nums, numsSize, sizeof(int), cmp);
 
+    for (int i = 0; i < numsSize - 2 && nums[i] <= 0; ++i) {
+        if (i > 0 && nums[i] == nums[i - 1]) continue;
+        int j = i + 1, k = numsSize - 1;
+        while (j < k) {
+            int sum = nums[i] + nums[j] + nums[k];
+            if (sum < 0) {
+                ++j;
+            } else if (sum > 0) {
+                --k;
+            } else {
+                if (*returnSize >= cap) {
+                    cap *= 2;
+                    ans = (int**) realloc(ans, sizeof(int*) * cap);
+                    *returnColumnSizes = (int*) realloc(*returnColumnSizes, sizeof(int) * cap);
+                }
+                ans[*returnSize] = (int*) malloc(sizeof(int) * 3);
+                ans[*returnSize][0] = nums[i];
+                ans[*returnSize][1] = nums[j];
+                ans[*returnSize][2] = nums[k];
+                (*returnColumnSizes)[*returnSize] = 3;
+                (*returnSize)++;
+
+                ++j;
+                --k;
+                while (j < k && nums[j] == nums[j - 1]) ++j;
+                while (j < k && nums[k] == nums[k + 1]) --k;
+            }
+        }
+    }
+    return ans;
+}
 ```
 
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