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

C++: #include <cstdio>
#include <algorithm>
#include <queue>
using namespace std;
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[100];
int *d;

void dijkstra() {
    priority_queue<pair<int, int>> PQ;
    int d[n], color[n];

    for (int i = 0; i < n; i++) {
        d[i] = INFTY;
        color[n] = WHITE;
    }
    d[0] = 0;
    PQ.push(make_pair(0, 0));

    while (!PQ.empty()) {
        pair<int, int> f = PQ.top();
        PQ.pop();

        int u = f.second;
        color[u] = BLACK;

        if (d[u] < f.first * (-1)) { continue; }

        for (int j = 0; j < adj[u].size(); j++) {
            int v = adj[u][j].first;
            if (color[v] == BLACK) { continue; }
            if (d[u] + adj[u][j].second < d[v]) {
                d[v] = d[u] + adj[u][j].second;
                // printf("d[%d] = %d\n", v, d[v]);
                PQ.push(make_pair(d[v] * (-1), v));
                color[v] = GRAY;
            }
        }
    }
    
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i, d[i]);
    }
}

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

    // adj = new vector<pair<int, int>>[n];

    for (int i = 0; i < n; i++) {
        int u, k;
        scanf("%d %d", &u, &k);
        for (int j = 0; j < k; j++) {
            int v, c;
            scanf("%d %d", &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 ,M[MAX][MAX];

void dijkstra(){
    int minv;
    //d?????????????¨??????????????????¨????§????????????????????????????
    int d[MAX],color[MAX];
    for(int i=0;i<n;i++){
        d[i] = INFTY;
        color[i] = WHITE;
    }
    d[0] = 0;
    color[0] = GRAY;
    
    while(true){
        minv = INFTY;
        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]!= 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(int argc, const char * argv[]) {
    int n;
    cin >> n;
    
    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)
            M[i][j] = INFTY;
    
    int u,k,v,c;
    
    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;
}

C++: #define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
using namespace std;
const int INF = 2000000000;
const int num = 100;
int n, u, k, v, w;
int m[num][num];
int d[num];
int c[num];
int main() {
	cin >> n;
	fill(m[0], m[num], INF);
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			cin >> v >> w;
			m[u][v] = w;
		}
	}
	fill(d, d + num, INF);
	fill(c, c + num, 0);
	d[0] = 0;
	while (true) {
		int ne = -1;
		int minv = INF;
		for (int i = 0; i < n; i++)
			if (!c[i] && d[i] < minv) {
				ne = i;
				minv = d[i];
			}
		if (ne == -1) break;
		c[ne] = 1;
		for (int i = 0; i < n; i++) {
			if (d[i] > d[ne] + m[ne][i]) d[i] = d[ne] + m[ne][i];
		}
	}
	for (int i = 0; i < n; i++)
		cout << i << " "<< d[i] << endl;
	return 0;
}