用set构造,优先队列和堆也能够
/* ID:kevin_s1 PROG:humble LANG:C++ */ #include <iostream> #include <cstdio> #include <string> #include <cstring> #include <vector> #include <map> #include <set> #include <algorithm> #include <cstdlib> #include <list> #include <cmath> using namespace std; #define MAXK 110 //gobal variable==== int K, N; long int S[MAXK]; set<long int> humble; //================== //function========== //================== int main(){ freopen("humble.in","r",stdin); freopen("humble.out","w",stdout); cin>>K>>N; for(int i = 1; i <= K; i++){ cin>>S[i]; humble.insert(S[i]); } for(int i = 1; i <= K; i++){ set<long int>::iterator iter = humble.begin(); while(1){ long int tmp = (*iter) * S[i]; if(tmp < 0) break; if(humble.size() > N){ humble.erase(--humble.end()); if(tmp > (*(--humble.end()))) break; } humble.insert(tmp); iter++; } } cout<< *(--humble.end())<<endl; return 0; }