Add solution for Problem:167 in C lang

src/167.c

@@ -0,0 +1,28 @@
+/**
+ * Return an array of size *returnSize containing the 1-based indices of two numbers 
+ * that add up to the target.
+ * Note: The returned array must be malloced, assume caller calls free().
+ */
+#include <stdlib.h>
+int* twoSum(int* numbers, int numbersSize, int target, int* returnSize) {
+ *returnSize = 2;
+ int* output = (int*)malloc(2 * sizeof(int));
+
+ int left =0;
+ int right = numbersSize-1;
+ while(left<right){
+ int sum = numbers[left] + numbers[right];
+ if(sum == target){
+ output[0] = left+1;
+ output[1] = right+1;
+ return output;
+ }
+ else if(sum<target){
+ left++;
+ }
+ else{
+ right--;
+ }
+ }
+ return NULL;
+}