Given an array of integers, return indices of the two numbers such that they add up to a specific target.

　　You may assume that each input would have exactly one solution, and you may not use the same element twice.

　　Example:

　　Given nums = [2, 7, 11, 15], target = 9,

　　Because nums[0] + nums[1] = 2 + 7 = 9,
　　return [0, 1].

• Difficulty:Easy
• Total Accepted:603.9K
• Total Submissions:1.7M
• Contributor:LeetCode

　　C code：

/**
 * Note: The returned array must be malloced, assume caller calls free().
 */
int* twoSum(int* nums, int numsSize, int target) {
    
    int* p;
    int i, j;

    p = malloc(sizeof(int)*2);

    for(i = 0
 
; i < numsSize; i++)
        for(j = 0; j < numsSize; j++)
        {
            if(nums[i] + nums[j] == target && i != j)
            {
                p[0] = j;
                p[1] = i;
                break;
            }
        }

    return p;
}

　　Submission Result: Accepted

　　題目是說給一個int *twoSum()函數，參數為指向整型數組的指針、數組的大小和一個數據，從數組中找到任意兩個數相加起來等於從主函數傳來的實參，返回數組中這兩個數的下標(note:下標不能相同，必須是兩個不同的數相加)。

LeetCode - two sum