Create: 0040-combination-sum-ii.c

Author: mdmzfzl

Diff for: c/0040-combination-sum-ii.c

@@ -0,0 +1,44 @@
+void backtrack(int *candidates, int candidatesSize, int target, int start, int *current, int currentSize, int **result, int *resultSize, int *returnColumnSizes) {
+    if (target == 0) {
+        result[*resultSize] = (int *)malloc(currentSize * sizeof(int));
+        returnColumnSizes[*resultSize] = currentSize;
+        for (int i = 0; i < currentSize; i++) {
+            result[*resultSize][i] = current[i];
+        }
+        (*resultSize)++;
+        return;
+    }
+    
+    for (int i = start; i < candidatesSize; i++) {
+        if (i > start && candidates[i] == candidates[i - 1]) {
+            continue;  // Skip duplicates to avoid duplicate combinations
+        }
+        
+        if (candidates[i] > target) {
+            break;  // Since the array is sorted, we can exit early
+        }
+        
+        current[currentSize] = candidates[i];
+        backtrack(candidates, candidatesSize, target - candidates[i], i + 1, current, currentSize + 1, result, resultSize, returnColumnSizes);
+    }
+}
+
+int compare(const void *a, const void *b) {
+    return (*(int *)a - *(int *)b);
+}
+
+int** combinationSum2(int* candidates, int candidatesSize, int target, int* returnSize, int** returnColumnSizes) {
+    qsort(candidates, candidatesSize, sizeof(int), compare);
+    
+    int **result = (int **)malloc(1000 * sizeof(int *));
+    int *current = (int *)malloc(candidatesSize * sizeof(int));
+    *returnColumnSizes = (int *)malloc(1000 * sizeof(int));
+    
+    int resultSize = 0;
+    backtrack(candidates, candidatesSize, target, 0, current, 0, result, &resultSize, *returnColumnSizes);
+    
+    free(current);
+    
+    *returnSize = resultSize;
+    return result;
+}