Bulbs
来源:互联网 发布:网络摄监控系统图 编辑:程序博客网 时间:2024/05/21 08:50
Description
Vasya wants to turn on Christmas lights consisting of m bulbs. Initially, all bulbs are turned off. There are n buttons, each of them is connected to some set of bulbs. Vasya can press any of these buttons. When the button is pressed, it turns on all the bulbs it's connected to. Can Vasya light up all the bulbs?
If Vasya presses the button such that some bulbs connected to it are already turned on, they do not change their state, i.e. remain turned on.
Input
The first line of the input contains integers n and m (1 ≤ n, m ≤ 100) — the number of buttons and the number of bulbs respectively.
Each of the next n lines contains xi (0 ≤ xi ≤ m) — the number of bulbs that are turned on by the i-th button, and then xi numbers yij (1 ≤ yij ≤ m) — the numbers of these bulbs.
Output
If it's possible to turn on all m bulbs print "YES", otherwise print "NO".
Sample Input
Input
3 4
2 1 4
3 1 3 1
1 2
Output
YES
Input
3 3
1 1
1 2
1 1
Output
NO
Hint
Vasya wants to turn on Christmas lights consisting of m bulbs. Initially, all bulbs are turned off. There are n buttons, each of them is connected to some set of bulbs. Vasya can press any of these buttons. When the button is pressed, it turns on all the bulbs it's connected to. Can Vasya light up all the bulbs?
If Vasya presses the button such that some bulbs connected to it are already turned on, they do not change their state, i.e. remain turned on.
Input
The first line of the input contains integers n and m (1 ≤ n, m ≤ 100) — the number of buttons and the number of bulbs respectively.
Each of the next n lines contains xi (0 ≤ xi ≤ m) — the number of bulbs that are turned on by the i-th button, and then xi numbers yij (1 ≤ yij ≤ m) — the numbers of these bulbs.
Output
If it's possible to turn on all m bulbs print "YES", otherwise print "NO".
Sample Input
Input
3 4
2 1 4
3 1 3 1
1 2
Output
YES
Input
3 3
1 1
1 2
1 1
Output
NO
Hint
In the first sample you can press each button once and turn on all the bulbs. In the 2 sample it is impossible to turn on the 3-rd lamp.
#include<stdio.h>int main(){int a,b,i,g,j,f,k,sum;int c[100],s[100][100];while(scanf("%d%d",&a,&b)!=EOF){g=0;f=0;for(i=0;i<a;i++){scanf("%d",&c[i]);for(j=0;j<c[i];j++)scanf("%d",&s[i][j]);}for(i=0;i<a;i++)f+=c[i];for(k=1;k<=b;k++){sum=0;for(i=0;i<a;i++){for(j=0;j<c[i];j++){if(s[i][j]!=k)sum++;}}if(sum==f) g++;}if(g!=0)printf("NO\n");elseprintf("YES\n");}return 0;}
0 0
- Bulbs
- Bulbs
- Bulbs
- Bulbs
- Bulbs
- hdoj5600N bulbs
- A. Bulbs
- CF615A Bulbs
- Codeforces Bulbs
- H - Bulbs
- 【codeforces】Bulbs
- 【codeforces】Bulbs
- ZOJ - 2976 Light Bulbs
- BNU16495:Light Bulbs
- HDOJ 5600 N bulbs
- hdu 5600 N bulbs
- hdu5601 N*M bulbs
- HDU 5600:N bulbs
- javabean,servlet,jsp区别联系
- 4.基于数据库表进行认证
- Codeforces Round #325 (Div. 2)
- 表单input中disabled提交后得不到值的解决办法
- 透过硅谷工程师文化看顾问的职业常青
- Bulbs
- 20160721最近三天安卓开发遇到的问题
- leetcode 237. Delete Node in a Linked List
- Javascript变量值的类型
- Virtualization Spectrum
- Hexo高级教程之插件开发
- Codeforces Bulbs
- HttpURLConnection从网上下载图片
- 线程池简介