两数之和

Posted 2021-05-29 zhou753099943

 

/*

 * 两数之和

给定一个整数数组nums和一个整数目标值target，

请你在该数组中找出和目标值target相等的两个整数，并返回它们的下标

*/

struct NodeIndex

{

    NodeIndex(){}

    NodeIndex(int i, int v): index(i), value(v){}

    int index = 0;

    int value = 0;

};

void getSumTarget()

{

    std::vector<int> nums;

    nums.push_back(1);

    nums.push_back(4);

    nums.push_back(6);

    nums.push_back(100);

    nums.push_back(5);

    nums.push_back(5);

    nums.push_back(2);

    nums.push_back(8);

    nums.push_back(9);

    std::vector<NodeIndex> postion;

    for (size_t i = 0; i < nums.size();++i)

    {

        postion.push_back(NodeIndex(i, nums[i]));

        std::cout<<"("<<i<<","<<nums[i]<<"),";

    }

    std::cout<<std::endl;

    int target = 10;

    std::sort(postion.begin(), postion.end(), [](NodeIndex a, NodeIndex b){

        return a.value < b.value;

    });

    for (const NodeIndex& it : postion)

    {

        std::cout<<it.value<<",";

    }

    std::cout<<std::endl;

    int min = nums.at(0);

    if(target < min)

        return;

    std::vector<std::pair<int, int>> target_nums;

    int left_index = 0;

    int right_index = nums.size() - 1;

    while (left_index < right_index)

    {

         NodeIndex node1 = postion[left_index];

         NodeIndex node2 = postion[right_index];

        int sum = node1.value + node2.value;

        if (sum == target)

        {

            target_nums.push_back(std::make_pair(node1.index,node2.index));

            left_index++;

            right_index--;

        }

        else if (sum > target)

            right_index--;

        else

            left_index++;

    }

    for(auto it : target_nums)

    {

        std::cout<<"["<<it.first<<","<<it.second<<"]|";

    }

    std::cout<<std::endl;

}