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++: //さっさと済ませられるところはさっさと済ましてしまう．ただし注意深く
#include <cstdio>
#include <iostream>
#define MAX_VERTEXES 100
#define NIL -1
#define INFTY 20000000// >100*100000

using namespace std;

//think easy make easy

int n;//num of vertexes(頂点)
int matrix_graph[MAX_VERTEXES+1][MAX_VERTEXES+1];//0オリジン
bool vertex_set[MAX_VERTEXES+1];///0オリジン
int current_mincost[MAX_VERTEXES+1];//現時点での各頂点への最小コスト
bool candidate[MAX_VERTEXES+1];//次にvertex_setに加える頂点の候補
int new_vertex;

void findNextVertex(){
	int min_tmp=INFTY;
	int next_tmp = NIL;
	
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			if(i == new_vertex && vertex_set[j] == false){//わかりやすいプログラムほど処理もすくない.
				//無駄のないプログラムの方がわかりよい
				if(matrix_graph[i][j]+current_mincost[i] < current_mincost[j]
				   && matrix_graph[i][j] != NIL){
					   current_mincost[j]  = matrix_graph[i][j]+current_mincost[i];
					   candidate[j] = true;
				}
			}
		}
	}
	for(int i=0;i<n;i++){
		if(candidate[i] == true && current_mincost[i] < min_tmp){
			min_tmp = current_mincost[i];
			next_tmp = i;
		}
	}
	vertex_set[next_tmp] = true;
	candidate[next_tmp] = false;
	new_vertex = next_tmp;
}

int main(){
	scanf("%d",&n);

	int v_num;
	int k;//v_numの出次数

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

	for(int i=0;i<n;i++){
		scanf("%d",&v_num);
		scanf("%d",&k);

		for(int j=0;j<k;j++){
			int v_num2;
			int cst;
			scanf("%d",&v_num2);
			scanf("%d",&cst);
			matrix_graph[v_num][v_num2] = cst;
		}
	}

	for(int i=0;i<n;i++){
		vertex_set[i] = false;
		current_mincost[i] = INFTY;
	}
	/*確認用
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			if(j<n-1) printf("%d ",matrix_graph[i][j]);
			else printf("%d\n",matrix_graph[i][j]);
		}
	}
	*/

	for(int i=0;i<n;i++){
		candidate[i] = false;
	}

	vertex_set[0] = true;
	current_mincost[0] = 0;
	new_vertex = 0;

	for(int i=1;i<n;i++){
		//for(int j=0;j<n;j++){
			//cout <<" " <<vertex_set[j] ;
		//}
		//cout <<endl;
		findNextVertex();
	}


	for(int i=0;i<n;i++){
		cout <<i <<" " <<current_mincost[i] <<endl;
	}


	return 0;
}

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

#define INF (1<<21)

int vis[101],M[101][101],d[101],p[101],n;

void dijkstra(){
    int minv,i,j,v;
    for( i = 1; i < n; i++ ){
        d[i] = INF;
        p[i] = -1;
    }
    while(1){
        minv = INF;
        int u = -1;
        for( i = 0; i < n; i++ ){
            if( minv>d[i] && !vis[i] ){
                minv = d[i];
                u = i;
            }
        }
        if( minv == INF ) break;
        vis[u]  = 1;
        for( v = 0; v < n; v++ ){
            if( !vis[i] && M[u][v]!=INF ){
                if( d[v] > d[u] + M[u][v] ){
                    d[v] = d[u] + M[u][v];
                }
            }
        }
    }
    for( i = 0; i < n ; i++ ){
        cout << i << " " << ( d[i]==INF? -1 : d[i] ) << endl;
    }
}

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

C++: #include<bits/stdc++.h>
using namespace std;
#define INF 10000000

// O(ElogE)

// pq<pair> はfirstが大きい順に出てくるのですか？
// s:= 開始ノード  v:= 頂点数  adjlist:= 隣接リスト (first:= コスト   second:= 行先)
vector<int> dijk(int s, int v, vector<vector<pair<int, int> > > adjlist){
    
    priority_queue <pair<int, int> > wait;
    vector<int> result(v, INF);

    //スタート地点を追加
    result[s] = 0;
    wait.push(make_pair(0, s));

    //ダイクストラ本体
    while(!wait.empty()){    //waitが空になるまで

        int nowpoint = wait.top().second;
        int nowcost = -wait.top().first;
        wait.pop();

        if(result[nowpoint] < nowcost) continue;


        //今いる頂点と隣接しているすべての頂点をなめる
        for(int i = 0; i < adjlist[nowpoint].size(); i++){

            int nextpoint = adjlist[nowpoint][i].second;
            int nextcost = nowcost + adjlist[nowpoint][i].first;
            //現時点より安く到達できそうであれば、結果を更新して優先度付きキューに格納
            if(result[nextpoint] > nextcost){
                result[nextpoint] = nextcost;
                wait.push(make_pair(-nextcost, nextpoint));
            }
        }
    }
    
    return result;         //結果列を返す
}

int main(){

    int V; cin >> V;
    vector<vector<pair<int, int> > > adjlist(V);      //first := コスト　second := 行先

    //入力
    for(int i = 0; i < V; i++){
        int gomi; cin >> gomi;
        int k; cin >> k;
        for(int j = 0; j < k; j++){
            int v, c; cin >> v >> c;           // a ,b 間に コスト c の辺がある
            adjlist[i].push_back(make_pair(c, v));
        }     
    }

    vector<int> result(V);
    result = dijk(0, V, adjlist);
    //cout << result[G] << endl;

    for(int i = 0; i < V; i++){
        cout << i << " " << result[i] << endl;
    }
    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, M[MAX][MAX];

void dijkstra() {
   int minv;
   int color[MAX], d[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 i = 0; i < n; i++) {
      	  if(minv > d[i] && color[i] != BLACK) {
  	      	  minv = d[i];
  	      	  u = i;
  	      }
      }
      if(u == -1) break;
      color[u] = BLACK;
      for(int v =  0; v < n; v++) {
      	  if(color[v] != BLACK && M[u][v] != INFTY) {
  	      	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] == INFTY ? -1 : d[i]) << endl; 
   }
}

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