Problem:
Single Source Shortest Path (Negative Edges)

Input

An edge-weighted graph G (V, E) and the source r.

|V| |E| r
s0 t0 d0
s1 t1 d1
:
s|E|-1 t|E|-1 d|E|-1

|V| is the number of vertices and |E| is the number of edges in G. The graph vertices are named with the numbers 0, 1,..., |V|-1 respectively. r is the source of the graph.

si and ti represent source and target vertices of i-th edge (directed) and di represents the cost of the i-th edge.

Output

If the graph contains a negative cycle (a cycle whose sum of edge costs is a negative value) which is reachable from the source r, print

NEGATIVE CYCLE

in a line.

Otherwise, print

c0
c1
:
c|V|-1

The output consists of |V| lines. Print the cost of the shortest path from the source r to each vertex 0, 1, ... |V|-1 in order. If there is no path from the source to a vertex, print "INF".

Constraints

1 ≤ |V| ≤ 1000

0 ≤ |E| ≤ 2000

-10000 ≤ di ≤ 10000

There are no parallel edges

There are no self-loops

Sample Input 1

4 5 0
0 1 2
0 2 3
1 2 -5
1 3 1
2 3 2

Sample Output 1

0
2
-3
-1

Sample Input 2

4 6 0
0 1 2
0 2 3
1 2 -5
1 3 1
2 3 2
3 1 0

Sample Output 2

NEGATIVE CYCLE

Sample Input 3

4 5 1
0 1 2
0 2 3
1 2 -5
1 3 1
2 3 2

Sample Output 3

INF
0
-5
-3

Solution in C# (judge verdict: Accepted)

using System;
using System.Text;
using System.Collections.Generic;
using System.Linq;
class Solve{
    public Solve(){}
    StringBuilder sb;
    public static int Main(){
        new Solve().Run();
        return 0;
    }
    void Run(){
        sb = new StringBuilder();
        Calc();
        Console.Write(sb.ToString());
    }
    void Calc(){
        string[] str = Console.ReadLine().Split(' ');
        int v = int.Parse(str[0]);
        int e = int.Parse(str[1]);
        int r = int.Parse(str[2]);
        int[] f = new int[e];
        int[] t = new int[e];
        long[] cost = new long[e];
        for(int i=0;i<e;i++){
            str = Console.ReadLine().Split(' ');
            f[i] = int.Parse(str[0]);
            t[i] = int.Parse(str[1]);
            cost[i] = int.Parse(str[2]);
        }
        BellmanFord B = new BellmanFord(f,t,cost,v,r,10000000000);
        if(B.NegativeCycle()){
            sb.Append("NEGATIVE CYCLE\n");
        }
        else{
            for(int i=0;i<v;i++){
                if(B.GetCost(i) == 10000000000){
                    sb.Append("INF\n");
                }
                else{
                    sb.Append(B.GetCost(i)+"\n");
                }
            }
        }
    }
}
class BellmanFord{
    bool NEGATIVECYCLE;
    long[] cost;
    public BellmanFord(int[] f,int[] t,long[] c,int n,int s,long INF){
        cost = new long[n];
        int e = f.Length;
        for(int i=0;i<n;i++){
            cost[i] = INF;
        }
        cost[s] = 0;
        for(int i=0;i<n;i++){
            for(int j=0;j<e;j++){
                if(cost[f[j]] != INF){
                    cost[t[j]] = Math.Min(cost[t[j]],cost[f[j]]+c[j]);
                }
            }
        }
        NEGATIVECYCLE = false;
        for(int i=0;i<e;i++){
            if(cost[f[i]] != INF && cost[f[i]]+c[i] < cost[t[i]]){
                NEGATIVECYCLE = true;
            }
        }
    }
    public bool NegativeCycle(){
        return NEGATIVECYCLE;
    }
    public long GetCost(int v){
        return cost[v];
    }
}