Problem:
Single Source Shortest Path

For a given weighted graph G(V, E) and a source r, find the source shortest path to each vertex from the source (SSSP: Single Source Shortest Path).

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

Print the costs of SSSP in the following format.

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| ≤ 100000

0 ≤ di ≤ 10000

0 ≤ |E| ≤ 500000

There are no parallel edges

There are no self-loops

Sample Input 1

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

Sample Output 1

0
1
3
4

Sample Input 2

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

Sample Output 2

3
0
2
INF

Solution in C++14 (judge verdict: Accepted)

#include<iostream>
#include<map>
#include<string>
#include<vector>
#include<algorithm>
#include<numeric>
#include<cmath>
#include<queue>
using namespace std;
int inf = 1000000000;

int dx[4] = {0,0,1,-1};
int dy[4] = {1,-1,0,0};

struct Dist{
  int to, from, dist;
};

int main(){
  int n, m, r;
  cin >> n >> m >> r;
  vector<int> v(n, inf);
  vector<Dist> c(m);
  for(int i=0; i<m; i++){
    int s, t, d;
    cin >> s >> t >> d;
    c[i].to = t; c[i].from = s; c[i].dist = d;
  }

  v[r] = 0;

  while( true ){
    bool f = false;
    for(int i=0; i<c.size(); i++){
      Dist d = c[i];
      if( v[d.from] != inf && v[d.to] > v[d.from] + d.dist ){
        v[d.to] = v[d.from] + d.dist;
        f = true;
      }
    }
    if( !f ) break;

  }

  for(int i=0; i<n; i++){
    if( v[i] == inf ) cout << "INF" << endl;
    else cout << v[i] << endl;
  }

  return 0;
}





// EOF