Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)

	g := makeGraph(n)
	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			c := getNextInt(scanner)
			g[u][v] = c
		}
	}

	ans := make([]int, n)
	im := make(IntMap, 1)
	im.increment(0)
	for len(im) < n {
		min := 1 << 30
		x := -1
		for u := range im {
			for v := 0; v < n; v++ {
				if im.get(v) != 0 {
					continue
				}
				if min > ans[u]+g[u][v] {
					min = ans[u] + g[u][v]
					x = v
				}
			}
		}
		im.increment(x)
		ans[x] = min
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i, ans[i]))
	}
	writer.Flush()
}

func makeGraph(n int) [][]int {
	g := make([][]int, n)
	for i := 0; i < n; i++ {
		g[i] = make([]int, n)
		for ii := 0; ii < n; ii++ {
			g[i][ii] = 1 << 30
		}
	}

	return g
}

// IntMap ...
type IntMap map[int]int

func (m IntMap) get(key int) int {
	if _, ok := m[key]; ok {
		return m[key]
	}
	return 0
}
func (m IntMap) increment(key int) {
	if _, ok := m[key]; ok == false {
		m[key] = 0
	}
	m[key]++
}

C++: #include <iostream>
#include <vector>
#include <queue>

#define INF 1000000000
using namespace std;

struct edge {
    int from;
    int to;
    int w;
};
struct node {
    node() : id {-1}, d {INF}, ns {} {};
    node(int i, vector<edge>& vec) : id {i}, d {INF}, ns {vec} {};
    int id;
    int d;
    vector<edge> ns;
};

vector<int> dijkstra(node* graph, int n, int st){
    auto ds = vector<int>(n, INF);
    auto comp = [](node& x, node& y){return x.d < y.d;};
    priority_queue<node, vector<node>, decltype(comp)> que(comp);
    node start = graph[st];
    start.d = 0;
    que.push(start);
    while(que.size()){
        node n = que.top();
        que.pop();
        if(n.d < ds[n.id]){
            ds[n.id] = n.d;
            for(auto e : n.ns){
                node next_n = graph[e.to];
                next_n.d = n.d + e.w;
                que.push(next_n);
            }
        }
    }
    return ds;
}

int main(){
    cin.sync_with_stdio(false);
    cout.sync_with_stdio(false);
    int n;
    cin >> n;
    node graph[n];
    for(int i = 0; i < n; ++i){
        int id;
        int m;
        cin >> id >> m;
        auto vec = vector<edge>(m);
        int v, c;
        for(int j = 0; j < m; ++j){
            cin >> v >> c;
            vec[j] = edge {id, v, c};
        }
        graph[id] = node(id, vec);
    }
    auto ds = dijkstra(graph, n, 0);
    for(int i = 0; i < n; ++i){
        cout << i << ' ' << ds[i] << endl;
    }
}

C++: #define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <cstdlib>
#include <string>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <vector>
#include <set>
#include <stack>
#include <queue>
#include <map>

using namespace std;

static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;
static const int NIL = -1;
static const int MAX = 100;
static const int INFTY = 10000000;


int colors[MAX] = { WHITE };	//各頂点の訪問状態
int graph[MAX][MAX] = { INFTY };
int d[MAX] = { INFTY };		//原点からの各頂点の距離
int p[MAX] = { NIL };		//親頂点

void dijkstra(int n) {

    d[0] = 0;
    colors[0] = WHITE;

    while (true) {

	int mincost = INFTY;
	int u;

	for (int i = 0; i < n; i++) {
	    //まだコストが確定しておらず、かつ現時点で仮コストが出ているもの
	    if (colors[i] != BLACK&&d[i] != INFTY) {

		//より小さいコストの原点からの距離があったら
		if (d[i] < mincost) {
		    mincost = d[i];
		    u = i;
		}
	    }
	}

	if (mincost == INFTY) {
	    break;
	}

	colors[u] = BLACK;

	//確定した頂点uからの近隣探索
	for (int i = 0; i < n; i++) {
	    
	    //まだ確定しておらずvから辺があれば
	    if (colors[i] != BLACK&&graph[u][i] != INFTY) {


		//現時点でiに行くコストより
		//頂点uを経由した方がコストが小さかったら
		if (d[u]+graph[u][i] < d[i]) {
		    d[i] = d[u] + graph[u][i];
		    p[i] = u;
		}

	    }

	}

    }
}

int main() {

    //cin.tie(0);
    //ios::sync_with_stdio(false);
    
    int n; scanf("%d", &n);
    int u; //頂点
    int k; //vからの辺の数
    int v; //uにつながる頂点v
    int c; //コスト

    //グラフ初期化
    for (int i = 0; i < n; i++) {
	for (int j = 0; j < n; j++) {
	    graph[i][j] = INFTY;
	}
    }
    
    //距離d初期化
    for(int i = 0; i < n; i++) {
	d[i] = INFTY;
    }

    //グラフ読み込み
    for (int i = 0; i < n; i++) {
	scanf("%d", &u);
	scanf("%d", &k);
	for (int j = 0; j < k; j++) {
	    scanf("%d", &v);
	    scanf("%d", &c);
	    graph[u][v] = c;
	}
    }


    //ダイクストラ法
    dijkstra(n);

    //表示
    for (int i = 0; i < n; i++) {
	printf("%d %d\n", i, d[i]);
    }

    return 0;

}

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

#define MAX_VERTEX 100
#define INF 1000000

int cost[MAX_VERTEX][MAX_VERTEX];
int d[MAX_VERTEX];
bool used[MAX_VERTEX];

int main() {
  int vertex_num;
  cin >> vertex_num;

  for(int i = 0; i < vertex_num; i++) {
    d[i] = INF;
    used[i] = false;
    for(int j = 0; j < vertex_num; j++) {
      cost[i][j] = INF;
    }
  }

  for (int i = 0; i < vertex_num; i++) {
    int vertex, out;
    cin >> vertex >> out;
    for(int j = 0; j < out; j++) {
      int to, c;
      cin >> to >> c;
      cost[vertex][to] = c;
    }
  }

  d[0] = 0;
  while(true) {
    int vertex = -1;
    for(int u = 0; u < vertex_num; u++) {
      if(!used[u] && (vertex == -1 || d[u] < d[vertex])) {
        vertex = u;
      }
    }

    if (vertex == -1) break;

    used[vertex] = true;

    for(int u = 0; u < vertex_num; u++) {
      d[u] = min(d[u], d[vertex] + cost[vertex][u]);
    }
  }

  for(int i = 0; i < vertex_num; i++) {
    cout << i << " " << d[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 M[MAX][MAX], color[MAX], d[MAX], p[MAX];

int n;

void dijkstra(int s){
    int u = s;
    for(int u = 0; u < n; u++){
        color[u] = WHITE;
        d[u] = INFTY;
    }
    d[s] = 0;
    p[s] = -1;

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

        color[u] = BLACK;

        for(int v = 0; v < n; v++){
            if(color[v] != BLACK && M[u][v] != INFTY){
                if(d[u] + M[u][v] < d[v]){
                    d[v] = d[u] + M[u][v];
                    p[v] = u;
                    color[v] = GRAY;
                }
            }
        }
    }
}
int main(){
    cin >> n;
    int u, k, v, c;

    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(0);

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

    return 0;
}