HDU 1217 Arbitrage（java版）

import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner kb = new Scanner(System.in);
		int s=0;
		while (kb.hasNext()) {
			s++;
			int n = kb.nextInt();
			if(n==0)break;
			HashMap<String, Integer> map = new HashMap<String, Integer>();
			for (int i = 1; i <= n; i++) {
				map.put(kb.next(), i);
			}
			double map1[][] = new double[n + 1][n + 1];
			int m = kb.nextInt();
			while (m-- > 0) {
				String a = kb.next();
				double b = kb.nextDouble();
				String c = kb.next();
				map1[map.get(a)][map.get(c)] = b;
			}
			for (int i = 1; i <= n; i++) {
				for (int j = 1; j <= n; j++) {
					for (int k = 1; k <= n; k++) {
						if (map1[j][k] < map1[j][i] * map1[i][k]) {
							map1[j][k] = map1[j][i] * map1[i][k];
						}
					}
				}
			}
			boolean flag = false;
			for(int i=1;i<=n;i++){
				if(map1[i][i]>1){
					flag=true;
					break;
				}
			}
			if(flag){
				System.out.println("Case "+s+": Yes");
			}else{
				System.out.println("Case "+s+": No");
			}
		}
		kb.close();
	}
}