Go: package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
	"strconv"
)

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
const INF = 1 << 60

type Edge struct {
	to, cost int
}

type Node struct {
	id, cost int
}

type PQ []Node

func (pq PQ) Len() int           { return len(pq) }
func (pq PQ) Less(i, j int) bool { return pq[i].cost < pq[j].cost }
func (pq PQ) Swap(i, j int)      { pq[i], pq[j] = pq[j], pq[i] }

func (pq *PQ) Push(x interface{}) {
	*pq = append(*pq, x.(Node))
}

func (pq *PQ) Pop() interface{} {
	old := *pq
	n := len(old)
	x := old[n-1]
	*pq = old[0 : n-1]
	return x
}

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		E[id] = make([]Edge, k)
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id][j] = Edge{to, cost}
		}
	}

	d := make([]int, N)
	for i := 0; i < N; i++ {
		d[i] = INF
	}
	done := make([]bool, N)
	pq := &PQ{}
	heap.Init(pq)
	d[0] = 0
	heap.Push(pq, Node{0, 0})
	for pq.Len() > 0 {
		cur := heap.Pop(pq).(Node).id
		if done[cur] {
			continue
		}
		done[cur] = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+d[cur]
			if !done[to] && cost < d[to] {
				d[to] = cost
				heap.Push(pq, Node{to, cost})
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, d[i])
	}
	wtr.Flush()
}

C++: // #define _GLIBCXX_DEBUG // for STL debug (optional)
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <cfloat>
#include <climits>
#include <ctime>
#include <cassert>
#include <numeric>
#include <fstream>
#include <functional>
#include <bitset>
using namespace std;
using ll = long long int;
using int64 = long long int;
 
template<typename T> void chmax(T &a, T b) {a = max(a, b);}
template<typename T> void chmin(T &a, T b) {a = min(a, b);}
template<typename T> void chadd(T &a, T b) {a = a + b;}
 
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
const int INF = 1LL << 29;
const ll LONGINF = 1LL << 60;
const ll MOD = 1000000007LL;
 
int main() {
    int N; scanf("%d", &N);
    vector< vector< pair<int, int> > > G(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);
            G[u].emplace_back(v, c);
        }
    }

    vector<int> dist(N, INF), checked(N);
    dist[0] = 0, checked[0] = true;

    int u = 0;
    for(int i=0; i<N; i++) {
        for(auto e : G[u]) {
            int v, c; tie(v, c) = e;
            chmin(dist[v], dist[u] + c);
        }

        int ma = INF, v = 0;
        for(int k=0; k<N; k++) {
            if(checked[k]) continue;
            if(ma > dist[k]) {
                ma = dist[k];
                v = k;
            }
        }
        checked[v] = true;
        swap(u, v);
    }

    for(int i=0; i<N; i++) {
        printf("%d %d\n", i, dist[i]);
    }
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <set>
#include <cmath>
#include <cstring>
#include <iomanip>
#include <random>
#include <chrono>
#include <queue>
using namespace std;
typedef long long ll;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
#define INF 1000000000
#define MOD 1000000007
#define EPS 0.00000001


int main(){
//    隣接リスト入力
//    verify用 judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_12_C&lang=jp
    int V; cin >> V;
    struct edge {
        int to, cost;
    };
    vector<vector<edge>> T(V);
    priority_queue<PII, vector<PII>, greater<PII>> Q;
    vector<int> d(V, INF);

    for(int i=0; i<V; i++){
        int from; cin >> from;
        int k; cin >> k;
        T[i].resize(k);
        for(int j=0; j<k; j++)
            cin>> T[i][j].to >> T[i][j].cost;
    }

    Q.push(PII(0, 0));


//  辺が与えられた場合
//  verify用 judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_1_A&lang=jp
//    int V, E, S; cin >> V >> E >> S;
//    struct edge {
//        int to, cost;
//    };
//    vector<vector<edge>> T(V);
//    priority_queue<PII, vector<PII>, greater<PII>> Q;
//    vector<int> d(V, INF);
//
//    for(int i=0; i<E; i++){
//        int from, to, cost; cin >> from >> to >> cost;
//        edge e;
//        e.to = to;
//        e.cost = cost;
//        T[from].push_back(e);
//    }
//    Q.push(PII(0, S));

    while(!Q.empty()){
        
        PII p = Q.top();
        int from = p.second;
        int cost = p.first;
        Q.pop();
        
        if(cost > d[from]) continue;
        d[from] = cost;
        for(int i=0; i<T[from].size(); i++){
            edge e = T[from][i];
            if(d[e.to] > d[from] + e.cost){
                Q.push(PII(d[from] + e.cost, e.to));
            }
        }
    }

    for(int i=0; i<V; i++){
        cout << i << " ";
        if(d[i]==INF){
            cout << "INF" << endl;
        }else{
             cout << d[i] << endl;
        }
    }
    return 0;
}