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 <bits/stdc++.h>
#define MODNum 1000000007
#define WHITE  0
#define GRAY   1
#define BLACK  2
#define INFTY  2147483647
#define REP(type, i, a, b) for( type i = a; i < b; i++ )
typedef long long ll;

using namespace std;

int main (void) {
    int N;
    scanf("%d", &N);
    int u,v,k;
    int c[N][N];  /* 辺の重みを記録した隣接行列 */
    int color[N]; /* 頂点の訪問状態 */
    int d[N];     /* 最短コストの記録 */
    int p[N];     /* 最短経路木における頂点vの親 */
    int weight;
    /* Initialization */
    for ( int i = 0; i < N; i++ ){
        d[i]     = INFTY;
        color[i] = WHITE;
        p[i]     = -1;
        for ( int j = 0; j < N; j++ ) c[i][j] = INFTY;
    }
    /* グラフを読み込み */
    for ( int i = 0; i < N; i++ ){
        scanf("%d %d", &u, &k);
        for ( int j = 0; j < k; j++ ){
            scanf("%d %d", &v, &weight);
            c[u][v] = weight;
        }
    }
    /* 始点 */
    d[0]     = 0;
    color[0] = GRAY;
    int minv;

    while ( 1 ){
        minv = INFTY;
        u = -1;
        /* 確定していない値の中で最小のものを探す　*/
        for ( int i = 0; i < N; i++ ){
            if ( minv > d[i] && color[i] != BLACK ){
                u    = i;
                minv = d[i];
            }
        }
        if ( u == -1 ) break;
        color[u] = BLACK; /* 値を確定 */
        for ( v = 0; v < N; v++ ){
            if ( color[v] != BLACK && c[u][v] != INFTY ){
                /* まだ確定していない頂点との経路が存在するなら */
                if ( d[v] > d[u] + c[u][v] ){
                    /* 最短経路を探索、他にあるなら更新 */
                    d[v] = d[u] + c[u][v];
                    color[v] = GRAY;
                }
            }
        }

    }

    /* 各頂点までの最短距離 */
    for ( int i = 0; i < N; i++ ){
        printf("%d %d\n", i, d[i]);
    }

    return 0;
}

C++: //ALDS1_12B
#include <iostream>
using namespace std;

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

int n,M[MAX][MAX];

int dijkstra(){
 int minv;
 int d[MAX],color[MAX];
 for(int i=0;i<n;i++){
  d[i]=INF;
  color[i]=WHITE;
 }
 d[0]=0;
 color[0]=GRAY;
 while(true){
  minv=INF;
  int u=-1;
  for(int i=0;i<n;i++){
   if(minv>d[i] && color[i]!=BLACK){
    u=i;
    minv=d[i];
   }
  }
  if(u==-1) break;
  color[u]=BLACK;
  for(int v=0;v<n;v++){
   if(color[v]!=BLACK && M[u][v]!=INF){
    if(d[v]>d[u]+M[u][v]){
     d[v]=d[u]+M[u][v];
     color[v]=GRAY;
    }
   }
  }
 }
 for(int i=0;i<n;i++){
  cout<<i<<" "<<(d[i]==INF ? -1:d[i])<<endl;
 }
} 

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