LintCode C++代码Two Sum

Two Sum - Input array is sorted
思路：双循环

class Solution {public:    /*     * @param nums an array of Integer     * @param target = nums[index1] + nums[index2]     * @return [index1 + 1, index2 + 1] (index1 < index2)     */    vector<int> twoSum(vector<int> &nums, int target) {        // write your code here        int j = nums.size() - 1;        vector<int> answer;        for (int i =0; i <= j; i++) {            for (int k = i+1; k <= j; k++) {                if (nums[i] + nums[k] == target) {                    answer.push_back(i + 1);                    answer.push_back(k + 1);                    return answer;                }            }        }    }};

方法二；

class Solution {public:    vector<int> twoSum(vector<int>& numbers, int target) {        int l = 0, r = numbers.size() - 1;        while (l < r) {            int sum = numbers[l] + numbers[r];            if (sum == target)             return {l + 1, r + 1};            else if (sum < target)             ++l;            --r;        }        return {};    }};