careercup-排序和查找 11.7

#include<iostream>
#include<vector>
using namespace std;

struct people
{
    int weight;
    int lenght;
    people(int w,int l):weight(w),lenght(l){}
};

bool isValid(vector<people> &path,people &p)
{
    if(path.empty())
        return true;
    people tmp=path.back();
    return p.lenght<tmp.lenght&&p.weight<tmp.weight;
}

void helper(vector<people> &pp,int start,int &longSequence,vector<people> &path)
{
    if(start==pp.size())
    {
        if(longSequence<path.size())
            longSequence=path.size();
        return;
    }
    int i;
    for(i=start;i<pp.size();i++)
    {
        //该条件可以不成立，因此不能进入递归
        if(isValid(path,pp[i]))
        {
            path.push_back(pp[i]);
            helper(pp,i+1,longSequence,path);
            path.pop_back();
        }
    }
}

int getIncreasingSequence(vector<people> &pp)
{
    int longSequence=0;
    vector<people> path;
    helper(pp,0,longSequence,path);
    return longSequence;
}

int main()
{
    vector<people> p={people(1,1),people(2,2),people(3,3),people(4,4)};
    cout<<getIncreasingSequence(p)<<endl;
}