LC167

vector<int> twoSum(vector<int>& nums, int target) {
    int l=0;
    int r=nums.size()-1;
    vector<int> ans;
    while(l<r){
        if(nums[l]+nums[r]>target){
            r--;
        }else if(nums[l]+nums[r]==target){
            ans.push_back(l+1);
            ans.push_back(r+1);
            break;
        }else{
            l++;
        }
    }
    return ans;
}