"Damn Single (单身狗)" is the Chinese nickname for someone who is being single. You are supposed to find those who are alone in a big party, so they can be taken care of.
Input Specification:
Each input file contains one test case. For each case, the first line gives a positive integer N (<=50000), the total number of couples. Then N lines of the couples follow, each gives a couple of ID's which are 5-digit numbers (i.e. from 00000 to 99999). After the list of couples, there is a positive integer M (<=10000) followed by M ID's of the party guests. The numbers are separated by spaces. It is guaranteed that nobody is having bigamous marriage (重婚) or dangling with more than one companion.
Output Specification:
First print in a line the total number of lonely guests. Then in the next line, print their ID's in increasing order. The numbers must be separated by exactly 1 space, and there must be no extra space at the end of the line.
Sample Input:3 11111 22222 33333 44444 55555 66666 7 55555 44444 10000 88888 22222 11111 23333Sample Output:
5 10000 23333 44444 55555 88888
题目大意：点击查看
#include<cstdio>
#include<cstring>
#define N 100000
using namespace std;
int p[N],p1[N];
int n,m,a,b;
int main(){memset(p,0,sizeof(p)); scanf("%d",&n);for(int i=0 ;i<n ;i++){scanf("%d%d",&a,&b);p[a]=b; p[b]=a;}scanf("%d",&m);for(int i=0 ;i<m ;i++){scanf("%d",&p1[i]);}for(int i=0 ;i<m ;i++){if(p[p1[i]]==0){p[p1[i]]=-1;}else if(p[p1[i]]==1){}else if(p[p1[i]]==-1){}else{for(int j=i+1 ;j<m ;j++){if(p[p1[i]]==p1[j]){p[p1[i]]=1; p[p1[j]]=1;break;}}if(p[p1[i]]!=1) p[p1[i]]=-1;}}int cnt = 0;for(int i=0 ;i<N ;i++){if(p[i]==-1){cnt++;} }printf("%d\n",cnt);int flag =1;for(int i=0 ;i<N ;i++){if(p[i]==-1){if(flag){flag=0;printf("%05d",i);}else{printf(" %05d",i);}}}return 0;
}