Two Sum

#include <iostream>
#include <vector>

using namespace std;

class IndexData {
public:
    IndexData(){}
    int index;
    int value;
};
/*
 * 1.生成一个vector,并对vector的 value 进行排序
 * 2.两个指针,left, right, left < right
 * 3.如果 vector[left][1] + vector[right][1] > value, right--;
 * 4.如果 vector[left][1] + vector[right][1] < value, left--;
 * 5.如果 == , 返回, 注意返回index 的大小
 *
 */
class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        vector<IndexData*> v_data;
        vector<int> res;
        size_t num_size = nums.size();
        size_t i = 0;

        for (; i<num_size; i++) {
            IndexData* d = new IndexData();
            d->index = i;
            d->value = nums[i];
            v_data.push_back(d);
        }
        sort(v_data.begin(), v_data.end(), cmp);

        int left = 0;
        int right = num_size - 1;
        while (left < right) {
            while ((left < right) && ((v_data[left]->value + v_data[right]->value) > target)) {
                right--;
            }

            while ((left < right) && ((v_data[left]->value + v_data[right]->value) < target)) {
                left++;
            }

            if ((v_data[left]->value + v_data[right]->value) == target) {
                if(v_data[left]->index < v_data[right]->index) {
                    res.push_back(v_data[left]->index + 1);
                    res.push_back(v_data[right]->index + 1);
                } else {
                    res.push_back(v_data[right]->index + 1);
                    res.push_back(v_data[left]->index + 1);
                }
                break;
            }

        }
        
        for (i=0; i<num_size; i++) {
            if (NULL != v_data[i]) {
                delete v_data[i];
                v_data[i] = NULL;
            }
        }
        
        return res;

    }

private:
    static bool cmp(const IndexData* id1, const IndexData* id2) {
        return id1->value < id2->value;
    }

};



int main() {

    vector<int> v;
    v.push_back(3);
    v.push_back(2);
    v.push_back(4);
    Solution s;

    s.twoSum(v, 6);
    return 0;
}