167. Two Sum II

Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number.

The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2.

Note:

Your returned answers (both index1 and index2) are not zero-based.
You may assume that each input would have exactly one solution and you may not use the same element twice.

Example:

Input: numbers = [2,7,11,15], target = 9
Output: [1,2]
Explanation: The sum of 2 and 7 is 9. Therefore index1 = 1, index2 = 2.

这道题刚做的时候不知道题目让我返回什么...大小为 returnSize 的数组，返回值是个指针,这个指针指向一个长度为 returnSize 的 int 数组。

 1 /**
 2 * Return an array of size *returnSize.
 3 * Note: The returned array must be malloced, assume caller calls free().
 4 */
 5 int* twoSum(int* numbers, int numbersSize, int target, int* returnSize) {
 6     int mid,low=0,high=numbersSize-1,sum;
 7     int *nums=(int*)malloc(sizeof(int)*2); 
 8     while(low<=high){
 9         sum=numbers[low]+numbers[high];
10         if(sum==target){
11             nums[0]=low+1;
12             nums[1]=high+1;
13             break;
14         }    
15         else if(sum<target)    low++;
16         else high--;
17     }
18     *returnSize=2;
19     return nums;
20 }