Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

const BIG_COST = 200000

type Path struct {
	node int
	cost int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	nNodes := scanInt(sc)

	// 各頂点につながる頂点一覧を得るための隣接リスト
	graph := make([][]Path, nNodes)

	for i := 0; i < nNodes; i++ {
		u := scanInt(sc)
		k := scanInt(sc)
		graph[i] = make([]Path, k)
		for d := 0; d < k; d++ {
			graph[u][d] = Path{
				node: scanInt(sc),
				cost: scanInt(sc),
			}
		}
	}

	// 0 から各頂点への最小コストを保存する配列
	minCosts := make([]int, nNodes)

	minCosts[0] = 0
	for i := 1; i < nNodes; i++ {
		minCosts[i] = BIG_COST
	}

	// 各頂点が調査済みかどうかを保持する配列
	checked := make([]bool, nNodes)

	// 最小コストのパスを高速に取得するためのヒープ。
	// コストが小さいものほどルートに来るようにする。
	heap := NewHeap(func(a, b Path) bool {
		return a.cost < b.cost
	})

	heap.insert(Path{node: 0, cost: 0})
	for heap.size > 0 {
		u := heap.extractMax()

		// 隣接行列を使っていた時とは違い、ヒープには
		// 同じノードへのパスが複数含まれうる。そのため既によりコストの低い
		// パスが見つかっている場合は無視する。
		if minCosts[u.node] < u.cost {
			continue
		}

		checked[u.node] = true

		for _, v := range graph[u.node] {
			cost := v.cost + u.cost
			if !checked[v.node] && cost < minCosts[v.node] {
				minCosts[v.node] = cost
				heap.insert(Path{node: v.node, cost: cost})
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i, cost := range minCosts {
		fmt.Fprintf(w, "%d %d\n", i, cost)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

// --- From ALDS1_9_C: Priority Queue

type Heap struct {
	size   int
	heap   []Path
	isHigh func(a, b Path) bool
}

func NewHeap(isHigh func(a, b Path) bool) Heap {
	heap := make([]Path, 1) // 先頭は不使用
	return Heap{size: 0, heap: heap, isHigh: isHigh}
}

func (h *Heap) insert(v Path) {
	h.size += 1
	if h.size > len(h.heap)-1 {
		h.heap = append(h.heap, v)
	} else {
		h.heap[h.size] = v
	}

	for i := h.size; i > 1; {
		parent := i / 2
		if h.isHigh(h.heap[parent], h.heap[i]) {
			break
		}
		h.heap[i], h.heap[parent] = h.heap[parent], h.heap[i]
		i = parent
	}
}

func (h *Heap) extractMax() Path {
	if h.size <= 0 {
		panic("cannot extract from empty heap")
	}

	max := h.heap[1]
	h.heap[1] = h.heap[h.size]
	h.size -= 1
	h.maxHeapify(1)

	return max
}

func (h *Heap) maxHeapify(idx int) {
	left := idx * 2
	right := left + 1
	largest := idx

	if left <= h.size {
		if h.isHigh(h.heap[left], h.heap[idx]) {
			largest = left
		}
		if right <= h.size && h.isHigh(h.heap[right], h.heap[largest]) {
			largest = right
		}
	}

	if largest != idx {
		h.heap[idx], h.heap[largest] = h.heap[largest], h.heap[idx]
		h.maxHeapify(largest)
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
long long INF = 1000000000000000;
vector<long long> dijkstra(vector<vector<pair<int, int>>> &E, int s){
    int V = E.size();
    vector<long long> d(V, INF);
    priority_queue<pair<long long, int>, vector<pair<long long, int>>, greater<pair<long long, int>>> Q;
    Q.push(make_pair(0, s));
    while (!Q.empty()){
        long long c = Q.top().first;
        int v = Q.top().second;
        Q.pop();
        if (d[v] == INF){
            d[v] = c;
            for (int i = 0; i < E[v].size(); i++){
                Q.push(make_pair(c + E[v][i].first, E[v][i].second));
            }
        }
    }
    return d;
}
int main(){
    int n;
    cin >> n;
    vector<vector<pair<int, int>>> E(n);
    for (int i = 0; i < n; i++){
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++){
            int v, c;
            cin >> v >> c;
            E[u].push_back(make_pair(c, v));
        }
    }
    vector<long long> d = dijkstra(E, 0);
    for (int i = 0; i < n; i++){
        cout << i << ' ' << d[i] << endl;
    }
}

C++: #include <stdio.h>
#include <queue>
#include <vector>
#include <functional>

#define N 100
using namespace std;


class list {
public:
	int cost;
	int node;
	int from;
	list(void) {
		cost = -1;
		node = -1;
		from = -1;
	}
};

bool operator<(const list& y,const list& x) {
	return (y.cost < x.cost);
};
bool operator>(const list& y,const list& x) {
	return (y.cost>x.cost);
};

list m[N][N];
bool visited[N];
int sum = 0;
int dist[N];

int main(void) {
	priority_queue<list, vector<list>, greater<list> > pq;
	int n;
	int now;
	int work;
	int k[N];
	int u;
	scanf("%d", &n);
	for (int i = 0; i<n; i++) {
		visited[i] = false;
		scanf("%d", &u);
		scanf("%d", &k[u]);
		for (int j = 0; j < k[u]; j++) {
			int a, b;
			scanf("%d", &a);
			scanf("%d", &b);
			m[u][j].cost = b;
			m[u][j].node = a;
		}
	}
	now = 0;
	dist[now] = 0;
	while (1) {
		//printf("I'm in %d\n", now);
		visited[now] = true;
		for (int j = 0; j<k[now]; j++) {
				list a;
				a.cost = m[now][j].cost;
				a.node = m[now][j].node;
				a.from=now;
				pq.push(a);
				//printf("I pushed %d %d\n", a.node, a.cost);
		}
		//system("pause");
		list x;
		while (!pq.empty()) {
			if (visited[(pq.top()).node] == false) {
				x = pq.top();
				//printf("I got %d %d %d %d\n", x.node, x.cost,sum,x.from);
				pq.pop();
				now = x.node;
				sum += x.cost;
				dist[now] = dist[x.from]+x.cost;
				break;
			}
			else pq.pop();
		}
		if (x.node == -1)break;
	}
	for (int i = 0; i < n; i++) printf("%d %d\n", i, dist[i]);
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
static const int INFTY = 2000000000;
static const int NIL = -1;
static const int MAX = 10000;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int,int> > adj[MAX];

void dijkstra(int a[]){
    priority_queue<pair<int,int> > PQ;
    int color[MAX];
    int d[MAX];
    for(int i=0;i<n;i++){
        d[i] = INFTY;
        color[i] = WHITE;
    }

    d[0] = 0;
    PQ.push(make_pair(0,0));
    color[0] = GRAY;

    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[v] > d[u] + adj[u][j].second){
                d[v] = d[u] + adj[u][j].second;
                //priority_queue???DEFAULT??§??§?????????????????????????????????-1??????????????????
                PQ.push(make_pair(d[v] * (-1),v));
                color[v] = GRAY;
            }
        }
    }

    for(int i=0;i<n;i++) a[i] = d[i];
}

int main(){
    int k,u,v,c;

    scanf("%d",&n);
    for(int i=0;i<n;i++){
        scanf("%d %d",&u,&k);
        for(int j=0;j<k;j++){
            scanf("%d %d",&v,&c);
            adj[u].push_back(make_pair(v,c));
        }
    }
    int a[MAX];
    dijkstra(a);
    
    for(int i=0;i<n;i++){
            printf("%d %d\n",i,a[i]);
    }

    return 0;
}