力扣题目【两数之和】变种

原题目

原题输入的数组是无序的，使用双指针来解题的时候遇到了问题。如果修改题目条件为输入的数组都是降序或者升序排列，那么就可以使用双指针法

code

#include
#include
#include
using namespace std;
class Solution {
public:
    vector twoSum(vector& nums, int target) {
        vector ress;
        int left;
        int right;
        sort(nums.begin(), nums.end());
        for (int left = 0; left < nums.size(); left++)
        {
            if (nums[left] > target)
            {
                return ress;
            }
            right = nums.size() - 1;
            while (right > left)
            {
                while (right > left && nums[left] + nums[right] > target)
                {
                    right--;
                }
                while (right > left && nums[left] + nums[right] < target)
                {
                    left++;
                }
                if (nums[right] + nums[left] == target)
                {
                    ress = { left,right };
                    return ress;
                }
                else
                {
                    continue;
                }
            }


        }
        return ress;
    }
};
int main()
{
    vector A{ 2,3,4 };
    Solution SS;
    vector res = SS.twoSum(A, 5);
    cout << "[" << res[0] << "," << res[1] << "]" << endl;
    return 0;
}