ARBITRAG.cpp

/*
USER: zobayer
TASK: ARBITRAG
ALGO: warshall
*/

#include <cstdio>
#include <map>
#include <string>
#include <algorithm>
using namespace std;

#define MAX 30
#define EPS 1e-9

char res[2][4] = {"Yes","No"};
double value[MAX][MAX];
map< string, int > M;
map< string, int > :: iterator it;

inline int hash(char *s, int &n) {
	int ret; it = M.find(s);
	if(it == M.end()) M.insert(pair< string, int >(s, ret=n++));
	else ret = it->second;
	return ret;
}

int warshall(int n) {
	int i, j, k;
	for(k=0;k<n;k++) {
		for(i=0;i<n;i++)
			for(j=0;j<n;j++)
				value[i][j] = max(value[i][j], value[i][k]*value[k][j]);
		if(value[k][k] > 1.0 + EPS) return 0;
	}
	return 1;
}

int main() {
	int cs = 1, i, j, n;
	char name1[MAX], name2[MAX];
	double val;
	while(scanf("%d", &n)==1 && n) {
		M.clear();
		for(i = j = 0; i < n; i++) {
			scanf("%s", name1);
			hash(name1, j);
		}
		for(i = 0; i < n; i++) {
			for(j = 0; j < n; j++) value[i][j] = 0.0;
			value[i][i] = 1.0;
		}
		scanf("%d", &j);
		while(j--) {
			scanf("%s %lf %s", name1, &val, name2);
			value[M[name1]][M[name2]] = val;
		}
		printf("Case %d: %s\n", cs++, res[warshall(n)]); 
	}
	return 0;
}