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++: // C++ 14
#include <iostream>
#include <vector>
#include <list>
#include <algorithm>
#include <queue>
#include <stack>
#include <math.h>
#define ll long long
#define Int int
#define loop(x, start, end) for(Int x = start; x < end; x++)
#define loopdown(x, start, end) for(int x = start; x > end; x--)
using namespace std;
#define MAX_N 100
#define W_INF (1 << 21)


void sssp(Int W[MAX_N][MAX_N], Int n, Int ans[]) {
    ans[0] = 0;
    loop(i,1,n) ans[i] = W_INF;
    
    Int u = 0;
    loop(count,0,n) {
        loop(i,0,n) {
            loop(j,0,n) {
                if (W[i][j] != W_INF) {
                    ans[j] = min(ans[j], ans[i] + W[i][j]);
                }
            }
        }
        
        Int min_ = W_INF;
        loop(v,0,n) {
            if (W[u][v] < W_INF && ans[v] < min_) {
                min_ = ans[v], u = v;
            }
        }
    }
}


int main(void) {
  Int n, k, v, c, W[MAX_N][MAX_N];
  cin >> n;
  Int ans[n];
  loop(i,0,n) {
    loop(j,0,n) {
      W[i][j] = W[j][i] = W_INF;
    }
  }
  loop(u,0,n) {
    cin >> k >> k;
    loop(i,0,k) {
      cin >> v >> c;
      W[u][v] = c;
    }
  }
  sssp(W, n, ans);
  loop(i,0,n) cout << i << " " << ans[i] << endl;
}

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 stra(){
    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;
        }
    }
    stra();
    return 0;
}

C++: #include <bits/stdc++.h>
#define FOR(i, m, n) for(int i = m;i < n;i++)
#define REP(i,n) for(int i=0;i<n;i++)
#define FORq(i, m, n) for(int i = m;i <= n;i++)
#define SCD(n) scanf("%d",&n)
#define SCD2(m,n) scanf("%d%d",&m,&n)
#define PRINTD(n) printf("%d\n",n)
#define DEBUG printf("%s\n","debug")
using namespace std;
//////////////////////////////////////////////////////
//http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_12_B&lang=jp
struct Vertex {
	// edge information
	vector<int> edges_to; //to vertex number
	vector<int> edges_cost; // edge cost
	
	//for dijkstra
	bool done; //conform or not
	int cost; // now cost
	
	bool operator<(const Vertex& another) const { // priority --> min
        return another.cost < cost; // order(cost)
    }
	
	bool operator==(const Vertex& another) const {
        return another.cost == cost; // order(cost)
    }
};

const int V_MAX = 10003;
struct Vertex v[V_MAX];


int main(){
	priority_queue<Vertex>Q;
	int n; // vertex 0-indexed
	SCD(n);
	REP(i,n){ // 0-indexed
		int u,k;
		SCD2(u,k);
		REP(j,k){
			int nv,c; // to edge , its cost
			SCD2(nv,c);
			v[u].edges_to.push_back(nv);
			v[u].edges_cost.push_back(c);
		}
	}
	
	REP(i,n){
		v[i].done = false;
		v[i].cost = -1;
	}
	
	v[0].cost = 0; //start
	Q.push(v[0]);
	
	while (!Q.empty()){
		Vertex nowV = Q.top(); Q.pop();
		nowV.done = true;
		
		REP(i,nowV.edges_to.size()){
			int nto = nowV.edges_to[i];
			int ncost = nowV.cost + nowV.edges_cost[i];
			if (((v[nto].cost) < 0) or (ncost < v[nto].cost)){  //not visited or required refresh
				v[nto].cost = ncost;
				Q.push(v[nto]);
			
			}
			
		}
	}
	
	REP(i,n){ // output
		printf("%d %d\n",i,v[i].cost);
	}
	
	
}

C++: #include<bits/stdc++.h>
using namespace std;
#define ll long long 

	
const int INF = 7+(1e+9);
typedef int Weight;
struct Edge {  //src:辺の始点,dst:辺の終点,weight:辺の重さ
  int src, dst;
  Weight weight;
  Edge(int src, int dst, Weight weight) :
    src(src), dst(dst), weight(weight) { }
};
bool operator < (const Edge &e, const Edge &f) {
  return e.weight != f.weight ? e.weight > f.weight : //辺は重さが重いものを"小さい"と定義する
    e.src != f.src ? e.src < f.src : e.dst < f.dst;
}
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;

//引数 g:隣接リスト,s:始点,dist:各頂点までの距離が入る,prev:最短路木の親頂点が入る
//戻値 なし
void shortestPath(const Graph &g,int s,vector<Weight> &dist,vector<int> &prev) {
  int n = g.size();
  dist.assign(n, INF); dist[s] = 0;
  prev.assign(n, -1);
  priority_queue<Edge> Q;
  Q.push(Edge(-2, s, 0));
  while(!Q.empty()) {
    Edge e = Q.top(); Q.pop();
    if (prev[e.dst] != -1) continue;
    prev[e.dst] = e.src;
    for(auto f=g[e.dst].begin();f!=g[e.dst].end();f++){
      if (dist[f->dst] > e.weight+f->weight) {
        dist[f->dst] = e.weight+f->weight;
        Q.push(Edge(f->src, f->dst, e.weight+f->weight));
      }
    }
  }
}
 


int main(){
  int v; cin >> v;
  Graph g(v);    //頂点数vの空隣接リストgを生成
  for(int i=0;i<v;i++){
        int u,k; cin >>u >>k;
        for(int j=0;j<k;j++){
            int vv,cc; cin >>vv >>cc;
            g[u].push_back(Edge(u,vv,cc));    //隣接リストgにsからtに向かう重さwの辺を追加
        }
  }
  vector<Weight> dist;
  vector<int> prev;
  shortestPath(g,0,dist,prev);
  for(int i=0;i<v;i++){
        cout<<i<<" "<<dist[i]<<endl;
  }
  
}