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 <stdio.h>
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];
int d[MAX];

void dijkstra(int s) {
    int p[n];
    int color[n];
    
    for(int i=0; i<n; i++) {
        color[i] = WHITE;
        d[i] = INFTY;
        p[i] = -1;
    }
    
    d[s] = 0;
    
    while(1) {
        int u;
        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() {
    scanf("%d", &n);
    for (int i=0; i<n; i++) {
        for (int j=0; j<n; j++) {
            M[i][j] = INFTY;
        }
    }
    
    int u, k;
    for (int i=0; i<n; i++) {
        scanf("%d %d", &u, &k);
        for (int j=0; j<k; j++) {
            int index, tmp;
            scanf("%d %d", &index, &tmp);
            M[u][index] = tmp;
        }
    }
    
    dijkstra(0);
    
    for(int i=0; i<n; i++) {
        printf("%d %d\n", i, d[i]);
    }
    
    return 0;
}

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

using namespace std;

using vi = vector<int>;
using vvi = vector<vi>;
using pii = pair<int, int>;

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define IN(v) int v;cin>>v;
#define OUT(v) cout<<v<<endl
const int INF = 1000000000;

int main() {
  IN(N);

  vvi edge(N, vi(N, INF));
  REP(i, N) {
    IN(u);
    IN(k);
    REP(j, k) {
      IN(v); IN(c);
      edge[u][v] = c;
    }
  }

  int cost[N];
  priority_queue<pii, vector<pii>, greater<pii> > q;
  fill(cost, cost + N, INF);
  cost[0] = 0;
  q.push(make_pair(0, 0));

  while (!q.empty()) {
    pii p = q.top(); q.pop();
    int u = p.second;
    int cur_cost = p.first;

    if (cost[u] < cur_cost)
      continue;
    for (int v = 0; v < N; ++v) {
      if (edge[u][v] == INF)
        continue;
      if (cost[v] > cost[u] + edge[u][v]) {
        cost[v] = cost[u] + edge[u][v];
        q.push(make_pair(cost[v], v));
      }
    }
  }

  REP(i, N) {
    OUT(i << " " << cost[i]);
  }

  return 0;
}

C++: #include <stdio.h>
#define INF (1<<21)

int main(void)
{
 int i,j,n,m,u,k,l,v,c,a[10000],b[10000],d[10000][10000];

 scanf("%d",&n);
 
 for(i=0;i<n;i++){
 	scanf("%d %d",&u,&k);
 	a[i]=INF;
 	b[i]=0;
 	for(j=0;j<k;j++){
 		scanf("%d %d",&v,&c);
 		d[u][v]=c;
 	}
 }
 a[0]=0;
 
 while(1){
 	
 	l=-1;
 	m=INF;
 	
 	for(i=0;i<n;i++){
 		if(a[i]<m && b[i]=0){
 			m=a[i];
 			l=i;
 		}
 	}
 	
 	if(l==-1) break;
 	
 	b[l]=1;
 	
 	for(i=0;i<n;i++){
 		if(a[i]>=d[l][i]+a[l]) a[i]=d[l][i]+a[l];
 	}
 }
 
 for(i=0;i<n;i++){
 	if(a[i]==INF) printf("%d -1\n",i);
 	else printf("%d %d\n",i,a[i]);
 }
 
 return 0;
}

C++: #include <cstdio>
#include <algorithm>
#include <queue>
using namespace std;
static const int INFTY = (1 << 21);
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>
#include<queue>
#include<utility>
#include<stdio.h>
using namespace std;
typedef pair<int,int> P;
int main(){
  const int INF=(1<<29);
  int min[1010],fix[1010];
  int map[1010][1010];
  int s1; 
  int n,m,i,j,x,y,z,count=0; 
  priority_queue<P,vector<P>,greater<P> > que; 
  scanf("%d\n",&n);
  for(i=0;i<=n;i++){
    min[i]=INF,fix[i]=0;
  }
  for(i=0;i<=n;i++){
    for(j=0;j<=n;j++){
      map[i][j]=-1;
    }
  }
  for(i=0;i<n;i++){
    scanf("%d %d",&x,&m);
    for(j=0;j<m;j++){
      scanf("%d %d",&y,&z);
    if(map[x][y]==-1 || map[x][y]>z){
    map[x][y]=z;
    }
    }
    scanf("\n");
  }
  s1=0;
  que.push(P(0,s1));
  min[s1]=0;
  while(!que.empty()){
    P p=que.top();
    que.pop();
    int v=p.second;
    if(min[v]<p.first){
      continue;
    }
    for(i=0;i<=n;i++){
      if(map[v][i]!=-1 && min[i]>min[v]+map[v][i] && fix[i]==0){
        min[i]=min[v]+map[v][i];
        que.push(P(min[v]+map[v][i],i));
      }
    }
    fix[v]=1;
  }
  for(i=0;i<n;i++){
  printf("%d %d\n",i,min[i]);
  }
  return 0;
}