leetcode--1.two sum

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].

1.首先想直接到的是穷举，很简单就通过了

/** * Note: The returned array must be malloced, assume caller calls free(). */int* twoSum(int* nums, int numsSize, int target) {    int i,j;       int *p=(int*)malloc(sizeof(int)*2);    for (i=0;i<=numsSize;i++)        for (j=i+1;j<numsSize;j++)            if (nums[i]+nums[j]==target) {                p[0]=i;                p[1]=j;                break;            }    return p;}