zoukankan      html  css  js  c++  java
  • 在 n 道题目中挑选一些使得所有人对题目的掌握情况不超过一半。

    Snark and Philip are preparing the problemset for the upcoming pre-qualification round for semi-quarter-finals. They have a bank of n problems, and they want to select any non-empty subset of it as a problemset.

    k experienced teams are participating in the contest. Some of these teams already know some of the problems. To make the contest interesting for them, each of the teams should know at most half of the selected problems.

    Determine if Snark and Philip can make an interesting problemset!

    Input

    The first line contains two integers n, k (1 ≤ n ≤ 105, 1 ≤ k ≤ 4) — the number of problems and the number of experienced teams.

    Each of the next n lines contains k integers, each equal to 0 or 1. The j-th number in the i-th line is 1 if j-th team knows i-th problem and 0 otherwise.

    Output

    Print "YES" (quotes for clarity), if it is possible to make an interesting problemset, and "NO" otherwise.

    You can print each character either upper- or lowercase ("YeS" and "yes" are valid when the answer is "YES").

    Examples
    Input
    5 3
    1 0 1
    1 1 0
    1 0 0
    1 0 0
    1 0 0
    Output
    NO
    Input
    3 2
    1 0
    1 1
    0 1
    Output
    YES
    n 道题目中挑选一些使得所有人对题目的掌握情况不超过一半。
    #include<cstdio>
    #include<cstring>
    #include<algorithm>
    using namespace std;
    bool vis[22];
    int main(){
        int n,k,x;
        scanf("%d%d",&n,&k);
        for(int i=1;i<=n;++i) {
        int sum=0;
        for(int j=1;j<=k;++j) {
            scanf("%d",&x);
            if(x) sum+=1<<(j-1);
        }
        vis[sum]=1;
        }
        bool flag=0;
        for(int i=0;i<=15;++i) for(int j=0;j<=15;++j) if(((i&j)==0)&&vis[i]&&vis[j]) flag=1; 
        if(flag) puts("YES");else puts("NO");
    }
  • 相关阅读:
    C++ sort()函数的用法
    对C++里面 的知识积累:
    codevs 1160
    hdu 1020 Encoding
    poj 2591 Set Definition
    hdu 1505,1506
    hdu 1284 钱币兑换
    hdu 1231 最大连续子序列 ,1003 Max Sum;
    尺取法
    android OTA package packing and extract to partition
  • 原文地址:https://www.cnblogs.com/mfys/p/7749780.html
Copyright © 2011-2022 走看看