Go: package main

import (
	"strconv"
	"fmt"
	"bufio"
	"os"
)
const INF = 1 << 21
var scanner = bufio.NewScanner(os.Stdin)

func nextInt() int {
	scanner.Scan()
	i, e := strconv.Atoi(scanner.Text())
	if e != nil {
		panic(e)
	}
	return i
}


func main() {
	scanner.Split(bufio.ScanWords)
	n := nextInt()
	adj := make([][]int, n)
	for i := range adj {
		adj[i] = make([]int, n)
	}

	for i := 0;i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			v := nextInt()
			c := nextInt()
			adj[u][v] = c
		}
	}

	// for i := range adj {
	// 	fmt.Println(adj[i])
	// }

	dist := make([]int, n)
	prev := make([]int, n)
	visited := make([]bool, n)
	dijkstra := func(start int, size int) {
		for i := 0; i < size; i++ {
			dist[i] = INF
			prev[i] = -1
			visited[i] = false
		}
		dist[start] = 0
		for {
			u := -1
			tmp_min := INF
			for i := 0; i < size; i++ {
				if visited[i] == false && dist[i] < tmp_min {
					tmp_min = dist[i]
					u = i
				}
			}
			if u == -1 {
				break
			}
			visited[u] = true
			for i := 0; i < size; i++ {
				if adj[u][i] > 0 {
					w := adj[u][i]
					newlen := dist[u] + w
					if newlen < dist[i] {
						dist[i] = newlen
						prev[i] = u
					}
				}
			}
		}
	}
	dijkstra(0, n)
	for i, cost := range dist {
		fmt.Printf("%d %d\n", i, cost)
	}
}

C++: #include<iostream>
#include<algorithm>
#include<queue>
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1 << 20);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int, int> > adj[MAX];

void dijkstra() {
	priority_queue<pair<int, int> > PQ;
	int color[MAX], d[MAX];
	for(int i = 0; i < n; i++) {
		color[i] = WHITE;
		d[i] = INFTY;
	}
	
	d[0] = 0;
	PQ.push(make_pair(0, 0));
	color[0] = GRAY;
	
	while(!PQ.empty()) {
        pair<int, int> f = PQ.top();
		PQ.pop();
		int u = f.second;
		
		color[u] = BLACK;
		
		
		for(int j = 0; j < adj[u].size(); j++) {
			int v = adj[u][j].first;
			if(color[v] == BLACK) continue;
			if(d[v] > d[u] + adj[u][j].second) {
				d[v] = d[u] + adj[u][j].second;
				PQ.push(make_pair(d[v] * (-1), v));
				color[v] = GRAY;
			}
		}		
	}
	
	for(int i = 0; i < n; i++) {
		cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << endl;
	} 
}


int main() {
	int u, k, v, c;
	cin >> n;
	for(int i = 0; i < n; i++) {
		cin >> u >> k;
		for(int j = 0; j < k; j++) {
			cin >> v >> c;
			adj[u].push_back( make_pair(v, c));
		}
	}
	
	dijkstra();
	
	return 0;
}

C++: #include <iostream>
using namespace std;

static const int MAX = 100;
static const int INFTY = (1<<21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n,A[MAX][MAX];

void ant();

int main(){
  cin >> n;

  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++){
      A[i][j]=INFTY;
    }
  }

  int a,b,c,d;

  for(int i=0;i<n;i++){
    cin >> a >> b;
    for(int j=0;j<b;j++){
      cin >> c >> d;
      A[a][c]= d;
    }
  }
  ant();
  return 0;
}

void ant(){
  int minv,d[MAX],color[MAX];

  for(int i=0;i<n;i++){
    d[i]=INFTY;
    color[i]=WHITE;
  }
  d[0]=0;
  color[0]=GRAY;

  while(1){
    minv = INFTY;
    int u=-1;
    for(int j=0;j<n;j++){
      if(minv > d[j] && color[j]!=BLACK){
        u=j;
        minv=d[j];
      }
    }
    if(u==-1)break;

    color[u]=BLACK;

    for(int m=0;m<n;m++){
      if(color[m]!=BLACK && A[u][m]!=INFTY){
        if(d[m]>d[u]+A[u][m]){
          d[m]=d[u]+A[u][m];
          color[m]=GRAY;
        }
      }
    }
  }
  for(int i=0;i<n;i++){
    cout << i << " " << (d[i]==INFTY ? -1 : d[i]) << endl;
  }
}

C++: #include <iostream>
#include <algorithm>
#include <cmath>
#include <cstdio>
using namespace std;
#define MAX 10000000

int b[110];
bool used[110];
struct edge{int from, to, cost;};

int solve(int a[110][110], int n){
	b[0] = 0;
	//used[0] = true;
	while(1){
		int v = -1;
		for(int i = 0;i < n;i++){
			if(!used[i] && (v == -1 || b[v] > b[i]))v = i;
		}
		if(v == -1)break;
		used[v] = true;
		for(int i = 0;i < n;i++){
			if(a[v][i] != -1)b[i] = min(b[i], b[v] + a[v][i]);
		}
	}
	return 0;
}

int main(){
	int a[110][110], n;
	fill((int*)a, (int*)(a+110), -1);
	fill(b, b+110, MAX);
	fill(used, used, false);
	cin >> n;
	for(int i = 0;i < n;i++){
		int u, k, c, d;
		cin >> u >> k;
		for(int j = 0;j < k;j++){
			cin >> c >> d;
			a[u][c] = d;
		}
	}
	
	solve(a, n);
	for(int i = 0;i < n;i++){
		cout << i << " " << b[i] << endl;
	}
	
	return 0;
}
/*
5
0 3 2 3 3 1 1 2
1 2 0 2 3 4
2 3 0 3 3 1 4 1
3 4 2 1 0 1 1 4 4 3
4 2 2 1 3 3
*/

C++: #include <stdio.h>
#define N 101
#define INF 0xffffff
#define NIL 0

typedef enum {
  WHITE,
  BLACK,
} color_t;


int main(){
  int n, i, j, u ,k;
  int w[N][N]= {0}; // 0-origin w[u][v] : the weight of "node u -> node v"
  int adj[N][N];  // adj[u][i] : the adjency nodes of node u
  int v;
  int d[N], pi[N];
  color_t color[N];
  int mincost;
  int sum=0;

  for( i = 0 ; i < N ; i++){
    for( j = 0 ; j < N ; j++){
      w[i][j] = INF;
      adj[i][j] = INF;
    }
  }

  scanf("%d", &n);
  for ( i = 0; i < n; i++ ){
  scanf("%d", &u);
  scanf("%d", &k);
    for( j = 0 ; j < k ; j++){
      scanf("%d", &v);      
      scanf("%d", &w[u][v] );
      adj[u][j] = v;
    }
  }

  // initialize single source
  for( i = 0 ; i < N ; i++){
    d[i] = INF;
    pi[i]= NIL;
  }
  const int s = 0;
  d[s] = 0; // s: source
 
  // dijkstra()
  while(1){
    mincost = INF;
    for(i = 0 ; i < n ; i++){
      if( color[i] != BLACK && d[i] < mincost ){
	mincost = d[i];
	u = i;
      }
    }

    if(mincost == INF){
      break;
    }
    
    color[u] = BLACK; 
    for( i=0 ; i < n ; i++){
      v = adj[u][i];
      if( v == INF ){
	break;
      }
      if( color[v] != BLACK && (d[u] + w[u][v]) < d[v] ){
	pi[v] = u;
	d[v]  = d[u] + w[u][v];
      }
    }
    
  }

  // print
  sum = 0;
  for( i = 0 ; i < n ; i++ ){
    if( d[i] != INF ){
      printf("%d %d\n" ,i ,d[i]);
    }
  }

  return 0; // Don't forget return 0
}

C++: #include <bits/stdc++.h>
using namespace std;

const int MAX=105;
int state[MAX],N,D[MAX];
vector<pair<int,int>> S[MAX];
priority_queue<pair<int,int>> Q;

void dijkstra(){
    int cnt=1;
    for(int i=0;i<N;i++){
        state[i]=0;
        D[i]=100000000;
    }
    state[0]=1;
    D[0]=0;
    for(int i=0;i<S[0].size();i++){
        Q.push(make_pair(-S[0][i].second,S[0][i].first));
        D[S[0][i].first]=min(D[S[0][i].first],D[0]+S[0][i].second);
    }
    while(1){
        int a=Q.top().second;
        cout<<a<<endl;
        if(state[a]==0){
            Q.pop();
            state[a]=1;
            cnt++;
            for(int i=0;i<S[a].size();i++){
                if(state[S[a][i].first]==0){
                    Q.push(make_pair(-S[a][i].second,S[a][i].first));
                    D[S[a][i].first]=min(D[S[a][i].first],D[a]+S[a][i].second);
                }
            }
        }
        else Q.pop();
        if(cnt==N) break;
    }
    return;
}


int main(){
    
    cin>>N;
    for(int i=0;i<N;i++){
        int l,a;cin>>l>>a;
        for(int j=0;j<a;j++){
            int b,c;cin>>b>>c;
            S[i].push_back(make_pair(b,c));
        }
    }
    dijkstra();
    for(int i=0;i<N;i++){
        cout<<i<<" "<<D[i]<<endl;
    }
}