C++ make_heap,push_heap,pop_heap,sort_heap(以最大的K个数为例)

找出最大的20个数

#include <iostream>#include <algorithm>#include <numeric>#include <string>#include <array>#include <vector>#include <functional>#include <hash_set>#include <ctime>using namespace std;int main(){//freopen("C:\\in.txt","r",stdin);vector<int> t(50);iota(t.begin(),t.end(),1);random_shuffle(t.begin(),t.end());for_each(t.begin(),t.end(),[](int i){cout<<i<<endl;});cout<<endl;make_heap(t.begin(),t.begin()+21,greater<int>());for(auto it=t.begin()+21;it!=t.end();){push_heap(t.begin(),t.begin()+21,greater<int>());pop_heap(t.begin(),t.begin()+21,greater<int>());it=t.erase(t.begin()+20);}sort(t.begin(),t.end(),greater<int>());for_each(t.begin(),t.end(),[](int i){cout<<i<<endl;});return 0;}