# 2240. Arbitrage

## POJ 刷题系列：2240. Arbitrage

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;

public class Main{

String INPUT = "./data/judge/201712/P2240.txt";

public static void main(String[] args) throws IOException {
new Main().run();
}

class Edge{
int from;
int to;
double rate;

Edge(int from, int to, double rate){
this.from = from;
this.to   = to;
this.rate = rate;
}
}

List<Edge> edges;
boolean bellmanFord(int s, int n) {
double[] d = new double[n];
Arrays.fill(d, 0);
d[s] = 1;
boolean ok = false;
for (int i = 0; i < n; ++i) {
for (Edge e : edges) {
double nm = d[e.from] * e.rate;
if (nm > d[e.to]) {
d[e.to] = nm;
if (i == n - 1) {
ok = true;
}
}
}
}
return ok;
}

int T = 0;
while (true) {
int n = ni();
if (n == 0) break;
edges = new ArrayList<Edge>();

Map<String, Integer> map = new HashMap<String, Integer>();
for (int i = 0; i < n; ++i) {
String ns = ns();
map.put(ns, i);
}

int M = ni();
for (int i = 0; i < M; ++i) {
String from = ns();
double rate = nd();
String to   = ns();
}

if (bellmanFord(0, n)){
out.println("Case " + (++T) + ": Yes");
}
else {
out.println("Case " + (++T) + ": No");
}
}
}

FastScanner in;
PrintWriter out;

void run() throws IOException {
boolean oj;
try {
oj = ! System.getProperty("user.dir").equals("F:\\oxygen_workspace\\Algorithm");
} catch (Exception e) {
oj = System.getProperty("ONLINE_JUDGE") != null;
}

InputStream is = oj ? System.in : new FileInputStream(new File(INPUT));
in = new FastScanner(is);
out = new PrintWriter(System.out);
long s = System.currentTimeMillis();
out.flush();
if (!oj){
System.out.println("[" + (System.currentTimeMillis() - s) + "ms]");
}
}

public boolean more(){
return in.hasNext();
}

public int ni(){
return in.nextInt();
}

public long nl(){
return in.nextLong();
}

public double nd(){
return in.nextDouble();
}

public String ns(){
return in.nextString();
}

public char nc(){
return in.nextChar();
}

class FastScanner {
StringTokenizer st;
boolean hasNext;

public FastScanner(InputStream is) throws IOException {
hasNext = true;
}

public String nextToken() {
while (st == null || !st.hasMoreTokens()) {
try {
} catch (Exception e) {
hasNext = false;
return "##";
}
}
return st.nextToken();
}

String next = null;
public boolean hasNext(){
next = nextToken();
return hasNext;
}

public int nextInt() {
if (next == null){
hasNext();
}
String more = next;
next = null;
return Integer.parseInt(more);
}

public long nextLong() {
if (next == null){
hasNext();
}
String more = next;
next = null;
return Long.parseLong(more);
}

public double nextDouble() {
if (next == null){
hasNext();
}
String more = next;
next = null;
return Double.parseDouble(more);
}

public String nextString(){
if (next == null){
hasNext();
}
String more = next;
next = null;
return more;
}

public char nextChar(){
if (next == null){
hasNext();
}
String more = next;
next = null;
return more.charAt(0);
}
}

static class D{

public static void pp(int[][] board, int row, int col) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < row; ++i) {
for (int j = 0; j < col; ++j) {
sb.append(board[i][j] + (j + 1 == col ? "\n" : " "));
}
}
System.out.println(sb.toString());
}

public static void pp(char[][] board, int row, int col) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < row; ++i) {
for (int j = 0; j < col; ++j) {
sb.append(board[i][j] + (j + 1 == col ? "\n" : " "));
}
}
System.out.println(sb.toString());
}
}

static class ArrayUtils {

public static void fill(int[][] f, int value) {
for (int i = 0; i < f.length; ++i) {
Arrays.fill(f[i], value);
}
}

public static void fill(int[][][] f, int value) {
for (int i = 0; i < f.length; ++i) {
fill(f[i], value);
}
}

public static void fill(int[][][][] f, int value) {
for (int i = 0; i < f.length; ++i) {
fill(f[i], value);
}
}
}

static class Num{
public static <K> void inc(Map<K, Integer> mem, K k) {
if (!mem.containsKey(k)) mem.put(k, 0);
mem.put(k, mem.get(k) + 1);
}
}
}

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