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 <cstdio>
#include <cstring>
#define MAX 105
#define INF 1000000
using namespace std;

int n;
int color[MAX];//0 表示未进入 -1 表示在之中 1 表示已出去 
int p[MAX];
int M[MAX][MAX];
int d[MAX];

void dijkstra() {
	int i,j,u;
	d[0]=0;
	p[0]=-1;
	while(1) {
		int min=INF;
		u=-1;
		for(i=0;i<n;i++) {
			if(d[i]<min && color[i]!=1) {
				min=d[i];
				u=i;
			}
		}
		if(u==-1) break;
		color[u]=1;
		for(j=0;j<n;j++) {
			if(color[j]!=1 && d[j]>min+M[u][j]) {
				color[j]=-1;
				d[j]=min+M[u][j];
				p[j]=u;
			}
		}
	}
}

int main() {
	memset(d,INF,sizeof(d));
	memset(color,0,sizeof(color));
	memset(p,-1,sizeof(p));
	memset(M,INF,sizeof(M));
	int i,j,u,k,v,c;
	cin>>n;
	for(i=0;i<n;i++) {
		cin>>u>>k;
		for(j=0;j<k;j++) {
			cin>>v>>c;
			M[u][v]=c;
		}
	}
	dijkstra();
	for(i=0;i<n;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 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;
}