Source Code

Problem: 2983  User: yzhw 
Memory: 16960K  Time: 6172MS 
Language: Java  Result: Accepted 

Source Code 
import java.io.*;
import java.util.*;
public class Main {

	/**
	 * @param args
	 */
		static int c=0;
		static int g[]=new int[1001];
		static int next[]=new int[300000];
		static int val[]=new int[300000];
		static int v[]=new int[300000];
		//static LinkedList<Integer> q=new LinkedList<Integer>();
		static int n,m;
		static int count[]=new int[1001];
		static int len[]=new int[1001];
		static int s=-1,e=-1;
		static int q[]=new int[2000000];
		static boolean empty()
		{
			return s==e&&s!=-1;
		}
		static void push(int pos)
		{
			q[++s]=pos;
		}
		static int pop()
		{
			return q[++e];
		}
		static void insert(int s,int e,int value)
		{
			v[c]=e;
			next[c]=g[s];
			val[c++]=value;
			g[s]=c-1;
		}
		static boolean chk()
		{
			Arrays.fill(count, 0);
			Arrays.fill(len, 0xfffffff);
			s=e=-1;
			count[0]++;
			push(0);
			len[0]=0;
			while(!empty())
			{
				int top=pop();
				for(int p=g[top];p!=-1;p=next[p])
					if(len[v[p]]>len[top]+val[p])
					{
						len[v[p]]=len[top]+val[p];
						count[v[p]]++;
						push(v[p]);
						if(count[v[p]]>n+1)
							return false;
					}
			}
			return true;
		}
	public static void main(String[] args) throws IOException{
		Scanner in=new Scanner(new BufferedReader(new InputStreamReader(System.in)));
		while(in.hasNext())
		{
			n=in.nextInt();
			m=in.nextInt();
			Arrays.fill(g, -1);
			c=0;
			for(int i=0;i<m;i++)
			{
				String jud=in.next();
				if(jud.equals("P"))
				{
					int a=in.nextInt(),b=in.nextInt(),value=in.nextInt();
					insert(a,b,-value);
					insert(b,a,value);
				}
				else
				{
					int a=in.nextInt(),b=in.nextInt();
					insert(a,b,-1);
				}
			}
			for(int i=1;i<=n;i++)
				insert(0,i,0);
			if(chk())
				System.out.println("Reliable");
			else
				System.out.println("Unreliable");
		}

	}

}