leetcode2 Two Sum II – Input array is sorted

　　Two Sum II – Input array is sorted

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Question:

Similar to Question [1. Two Sum], except that the input array is already sorted in

ascending order.

同上题：先排序，然后从开头和结尾同时向中间查找，原理也比较简单。O(nlogn) runtime, O(1) space

      vector<int> twoSumSored(vector<int>& nums, int target){

        vector<int> vecCopy(nums);

        int i=0,n=2,l=0,r = nums.size()-1;

        sort(vecCopy.begin(),vecCopy.end());

        int j=nums.size()-1;

        while(i<j)

        {

                 int sum = nums[i]+nums[j];

                 if (sum <target)

                 {

                         i++;

                 }

                 else if (sum > target)

                 {

                         j--;

                 }

                 else

                 {

                         vector<int> index;

                         index.push_back(i+1);

                         index.push_back(j+1);

                         return index;

                 }

        }

}