PATA1121题解

水题。。

//
//  main.cpp
//  PATA1121
//
//  Created by Phoenix on 2018/2/24.
//  Copyright © 2018年 Phoenix. All rights reserved.
//

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
const int maxn = 100010;
int couple[maxn], exist[maxn] = {0};
bool flag[maxn] = {false};

int main(int argc, const char * argv[]) {
    fill(couple, couple + maxn, -1);
    int n, m;
    scanf("%d", &n);
    for(int i = 0; i < n; i++) {
        int a, b;
        scanf("%d %d", &a, &b);
        couple[a] = b;
        couple[b] = a;
    }
    scanf("%d", &m);
    for(int i = 0; i < m; i++) {
        int a;
        scanf("%d", &a);
        flag[a] = true;
    }
    int num = 0, k = 0;
    for(int i = 0; i < maxn; i++) {
        if(flag[i] == true) {
            if(flag[couple[i]] == false) num++;
        }
    }
    printf("%d\n", num);
    for(int i = 0; i < maxn; i++) {
        if(flag[i] == true && flag[couple[i]] == false){
            printf("%05d", i);
            if(k < num - 1) printf(" ");
            else printf("\n");
            k++;
        }
    }
    return 0;
}