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<cstdio>
#include<string>
#include<algorithm>
#include<vector>

#define INF 2000000001
#define MAX 101
#define NIL -1

using namespace std;

typedef struct {
    int toid;
    int far;
} PATH;

vector<PATH> D[MAX];
int N;
int Dist[MAX];

void dijkstra(){//0??????????????¢??????????????£?????????
    
    bool complete[MAX];
    vector<int> S;
    
    for (int i = 0; i < N; i++) {
        complete[i] = false;
        Dist[i] = INF;
    }
 
    //???????¨????
    Dist[0] = 0;
    S.push_back(0);
    int u=0,minf;
    complete[u] = true;
    
    while (1) {
        if (S.size() == N+1) break;
        
        //????????????
        for (int j = 0; j < D[S[u]].size(); j++) {
            if (!complete[D[S[u]][j].toid] && Dist[S[u]] + D[S[u]][j].far < Dist[D[S[u]][j].toid]) {
                Dist[D[S[u]][j].toid] = Dist[S[u]] + D[S[u]][j].far;
            }
        }
        
        u = NIL;
        minf = INF;
        
        //?¨??????´??°
        for (int i = 0; i < S.size(); i++) {
            
            for (int j = 0; j < D[S[i]].size(); j++) {
                if (Dist[D[i][j].toid] < minf && !complete[D[S[i]][j].toid]) {
                    minf = Dist[D[i][j].toid];
                    u = D[S[i]][j].toid;
                }
            }
            
        }
        S.push_back(u);
        complete[u] = true;
        u = S.size()-1;//????????§u????????§??¨????????????????????????
    }
}

int main(){
    cin >> N;
    for (int i = 0; i < N; i++) {
        int bb1,bb2;
        cin >> bb1 >> bb2;
        for (int j = 0; j < bb2; j++) {
            PATH bb3;
            cin >> bb3.toid >> bb3.far;
            D[i].push_back(bb3);
        }
    }
    
    dijkstra();
    
    for (int i = 0; i < N; i++) {
        printf("%d %d\n",i,Dist[i]);
    }
    
    return 0;
}

C++: #include<iostream>
using namespace std;
static const int MAX=100;
static const int INFTY=(1<<21);
static const int white=01;
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>>u>>c;
	    M[u][v]=c;
	}
    }
    dijkstra();
    return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <vector>
#include <queue>
#include <cmath>
using namespace std;
const int maxn=100+10;
const int maxv=10000+10;
const int INF=1<<21;
int n;
int E;
typedef struct
{
    int from,to,cost;
}Edge;

Edge e[maxv];
int d[maxn];
void bellman_ford(int s)
{
    fill(d,d+n,INF);
    d[s]=0;
    while(true)
    {
        bool bUpdate=false;
        for(int i=0;i<E;i++)
        {
            Edge es=e[i];
            if(d[es.from]!=INF&&d[es.to]>d[es.from]+es.cost)
            {
                d[es.to]=d[es.from]+es.cost;
                bUpdate=true;

            }
        }
        if(!bUpdate) break;

    }
    for(int i=0;i<n;i++)
    printf("%d %d\n",i,d[i]);
}
int main()
{
//    freopen("in.txt","r",stdin);
    scanf("%d",&n);
    int id,c;
    E=0;
    for(int i=0; i<n; i++)
    {
        scanf("%d%d",&id,&c);
        while(c--)
        {
            scanf("%d%d",&e[E].to,&e[E].cost);
            e[E].from=id;
            E++;
        }
    }
    bellman_ford(0);

    return 0;
}

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

int min(int i,int j){
 return i>j?j:i;
}

int main(void){
 int n,u,k,c,v;
 vector<int> d;
 vector< vector<int> > edge;
 cin>>n;
 edge.resize(n);
 for(int i=0;i<n;i++){
 edge[i].resize(n);
}
 d.resize(n);
 d[0]=0;
 for(int i=1;i<n;i++){
  d[i]=100000000;
}
 for(int i=0;i<n;i++){
  for(int j=0;j<n;j++){
   edge[i][j]=1000000000;
  }
}
for(int i=0;i<n;i++){
 edge[i][i]=0;
}
for(int i=0;i<n;i++){
 cin>>u>>k;
 for(int j=0;j<k;j++){
  cin>>v>>c;
  edge[u][v]=c;
 }
}
for(int i=0;i<n;i++){
 for(int j=0;j<n;j++){
  for(int k=0;k<i;k++){
  d[j]=min(d[j],d[k]+edge[k][j]);}
 }
}

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

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e18;
const int inf = 1e9;
#define rep(i, n) for (int i = 0; i < n; i++)
using Graph = vector<vector<int>>;
using pint = pair<int, int>;
int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
int dxx[8] = {1, 1, 1, 0, 0, -1, -1, -1}, dyy[8] = {-1, 0, 1, -1, 1, -1, 0, 1};

const int MAX = 100;
int cost[MAX][MAX];
int n;

void dijkstra() {
    int d[n];
    bool seen[n] = {};
    rep (i, n) { d[i] = inf; }
    d[0] = 0;
    while (1) {
        int minc = inf, now;
        rep (i, n) {
            if (minc > d[i] && !seen[i]) {
                minc = d[i];
                now = i;
            }
        }
        seen[now] = 1;
        if (minc == inf) break;
        rep (i, n) {
            if (cost[now][i] != inf && !seen[i]) {
                if (d[i] > cost[now][i] + d[now]) {
                    d[i] = cost[now][i] + d[now];
                }
            }
        }
    }
    rep (i, n) { cout << i << " " << d[i] << "\n"; }
    return;
}

int main() {
    cin >> n;
    rep (i, n) rep (j, n) cost[i][j] = inf;
    rep (i, n) {
        int now, k, next, c;
        cin >> now >> k;
        rep (i, k) {
            cin >> next >> c;
            cost[now][next] = c;
        }
    }
    dijkstra();
}