UVa 10919 - Prerequisites ? (Process the requirements as the input is read)

Link:https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=21&page=show_problem&problem=1860
Sol:

#include <bits/stdc++.h>
	using namespace std;
	map <string, bool> course;
	int main (){
	#ifndef ONLINE_JUDGE
	freopen("in.txt","r",stdin);
	#endif
	int k;
	while (scanf ("%d", &k)&&(k!=0)) {
	course.clear();
	int m;
	scanf ("%d", &m);
	map <string, bool> mapping;
	for (int i=0;i<k;i++) {
	string temp;
	cin >> temp;
	course[temp]=true;
	}
	int valid = true;
	for (int i=0;i<m;i++) {
	int n;
	scanf ("%d", &n);
	int num;
	scanf ("%d", &num);
	for ( int j=0;j<n;j++) {
	string temp;
	cin >> temp;
	if (course[temp]){
	num--;
	}
	}
	if (num>0) {
	valid = false;
	}
	}
	if (valid) {
	printf ("yes\n");
	}
	else {
	printf ("no\n");
	}
	}
	return 0;
	}