Go: package main

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

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}
func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}
func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}
func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 // for safety
	*pq = old[0 : n-1]
	return item
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := newQ()
	q.set(0, 0)
	visited := make(map[int]struct{})
	out := make([]int, n)

	for q.len() > 0 {
		u, d := q.pop()
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			dd := d + c
			if d, ok := q.get(uu); !ok || d > dd {
				q.set(uu, dd)
			}
		}

		out[u] = d
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

C++: #include<stdio.h>
#include<string.h>
int n, dis[105], a[105][105];
bool vst[105];
void dijkstra()
{
    memset(vst, 0, sizeof(vst));
    memset(dis, 0x3f3f3f3f, sizeof(dis));
    dis[0] = 0;
    for(int i = 0; i < n; i++)
    {
        int k = n;
        for(int j = 0; j < n; j++)
            if(!vst[j] && dis[k] > dis[j]) k = j;
        vst[k] = 1;
        for(int j = 0; j < n; j++)
            if(!vst[j] && dis[j] > dis[k] + a[k][j])
                dis[j] = dis[k] + a[k][j];
    }
}
int main()
{
    while(scanf("%d", &n) == 1)
    {
        memset(a, 0x3f3f3f3f, sizeof(a));
        for(int i = 1; i <= n; i++)
        {
            int m, j;
            scanf("%d%d", &m, &j);
            while(j--){
                int k, t;
                scanf("%d%d", &k, &t);
                if(t < a[m][k] || a[m][k] == -1) a[k][m] = a[m][k] = t;
            }
        }
        dijkstra();
        for(int i = 0; i < n; i++)
            printf("%d %d\n", i, dis[i]);        
    }
    return 0;
}

C++: #include "bits/stdc++.h"

using namespace std;

using ll = long long;
using ld = long double;

const int INF = (1 << 30) - 1;
const ll INF64 = ((ll)1 << 62) - 1;
const double PI = 3.1415926535897932384626433832795;

const int dx[] = { 0, 1, 0, -1 };
const int dy[] = { -1, 0, 1, 0 };

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	int n;
	cin >> n;

	vector<vector<pair<int, int>>> g(n);
	for (int i = 0; i < n; i++) {
		int k, v;
		cin >> k >> v;
		for (int j = 0; j < v; j++) {
			int u, c;
			cin >> u >> c;
			g[k].emplace_back(u, c);
		}
	}

	vector<int> dist(n, INF);
	dist[0] = 0;
	vector<bool> used(n);

	priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
	pq.emplace(0, 0);
	while (!pq.empty()) {
		pair<int, int> p = pq.top(); pq.pop();
		int v = p.second;

		if (dist[v] < p.first) {
			continue;
		}

		for (auto e : g[v]) {
			int to = e.first;
			int cost = e.second;
			if (dist[to] > dist[v] + cost) {
				dist[to] = dist[v] + cost;
				pq.emplace(dist[to], to);
			}
		}
	}

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

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

#define INF 1000000000
using namespace std;

struct edge {
    int from;
    int to;
    int w;
};
struct node {
    node() : id {-1}, d {INF}, ns {} {};
    node(int i, vector<edge>& vec) : id {i}, d {INF}, ns {vec} {};
    int id;
    int d;
    vector<edge> ns;
};

vector<int> dijkstra(node* graph, int n, int st){
    auto ds = vector<int>(n, INF);
    auto comp = [](node& x, node& y){return x.d < y.d;};
    priority_queue<node, vector<node>, decltype(comp)> que(comp);
    node start = graph[st];
    start.d = 0;
    que.push(start);
    while(que.size()){
        node n = que.top();
        que.pop();
        if(n.d < ds[n.id]){
            ds[n.id] = n.d;
            for(auto e : n.ns){
                node next_n = graph[e.to];
                next_n.d = n.d + e.w;
                que.push(next_n);
            }
        }
    }
    return ds;
}

int main(){
    cin.sync_with_stdio(false);
    cout.sync_with_stdio(false);
    int n;
    cin >> n;
    node graph[n];
    for(int i = 0; i < n; ++i){
        int id;
        int m;
        cin >> id >> m;
        auto vec = vector<edge>(m);
        int v, c;
        for(int j = 0; j < m; ++j){
            cin >> v >> c;
            vec[j] = edge {id, v, c};
        }
        graph[id] = node(id, vec);
    }
    auto ds = dijkstra(graph, n, 0);
    for(int i = 0; i < n; ++i){
        cout << i << ' ' << ds[i] << endl;
    }
}

C++: #define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <cstdlib>
#include <string>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <vector>
#include <set>
#include <stack>
#include <queue>
#include <map>

using namespace std;

static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;
static const int NIL = -1;
static const int MAX = 100;
static const int INFTY = 10000000;


int colors[MAX] = { WHITE };	//各頂点の訪問状態
int graph[MAX][MAX] = { INFTY };
int d[MAX] = { INFTY };		//原点からの各頂点の距離
int p[MAX] = { NIL };		//親頂点

void dijkstra(int n) {

    d[0] = 0;
    colors[0] = WHITE;

    while (true) {

	int mincost = INFTY;
	int u;

	for (int i = 0; i < n; i++) {
	    //まだコストが確定しておらず、かつ現時点で仮コストが出ているもの
	    if (colors[i] != BLACK&&d[i] != INFTY) {

		//より小さいコストの原点からの距離があったら
		if (d[i] < mincost) {
		    mincost = d[i];
		    u = i;
		}
	    }
	}

	if (mincost == INFTY) {
	    break;
	}

	colors[u] = BLACK;

	//確定した頂点uからの近隣探索
	for (int i = 0; i < n; i++) {
	    
	    //まだ確定しておらずvから辺があれば
	    if (colors[i] != BLACK&&graph[u][i] != INFTY) {


		//現時点でiに行くコストより
		//頂点uを経由した方がコストが小さかったら
		if (d[u]+graph[u][i] < d[i]) {
		    d[i] = d[u] + graph[u][i];
		    p[i] = u;
		}

	    }

	}

    }
}

int main() {

    //cin.tie(0);
    //ios::sync_with_stdio(false);
    
    int n; scanf("%d", &n);
    int u; //頂点
    int k; //vからの辺の数
    int v; //uにつながる頂点v
    int c; //コスト

    //グラフ初期化
    for (int i = 0; i < n; i++) {
	for (int j = 0; j < n; j++) {
	    graph[i][j] = INFTY;
	}
    }
    
    //距離d初期化
    for(int i = 0; i < n; i++) {
	d[i] = INFTY;
    }

    //グラフ読み込み
    for (int i = 0; i < n; i++) {
	scanf("%d", &u);
	scanf("%d", &k);
	for (int j = 0; j < k; j++) {
	    scanf("%d", &v);
	    scanf("%d", &c);
	    graph[u][v] = c;
	}
    }


    //ダイクストラ法
    dijkstra(n);

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

    return 0;

}