1 files changed, 32 insertions, 0 deletions
diff --git a/Computer_Science/leetcode/39-combination_sum.c~ b/Computer_Science/leetcode/39-combination_sum.c~
new file mode 100644
index 0000000..6b1dd4a
--- /dev/null
+++ b/Computer_Science/leetcode/39-combination_sum.c~
@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+/**
+ * Return an array of arrays of size *returnSize.
+ * The sizes of the arrays are returned as *columnSizes array.
+ * Note: Both returned array and *columnSizes array must be malloced, assume caller calls free().
+ */
+void backtracking(int** result, int current, int currentSize, int left, int* returnSize, int** columnSizes)
+{
+	if(left < 0)
+		return;
+	else if(left > 0)
+		return backtracking(result, current, currentSize + 1, left, returnSize);
+	else {
+		*(result + *returnSize) = malloc(sizeof(int) * currentSize);
+	}
+}
+
+int** combinationSum(int* candidates, int candidatesSize, int target, int** columnSizes, int* returnSize) {
+	int i;
+	int **result;
+	result = malloc(sizeof(int *) * 100);
+	if(candidatesSize == 0)
+		return NULL;
+
+	for(i = 0; i < candidatesSize; i++) {
+		backtracking(result, candidates[i], i + 1, target, returnSize, columnSizes);
+	}
+
+	return result;
+}