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 <iostream>
#include <vector>
#include <queue>

using namespace std;

#define MAX 10000
#define INF 1000000
#define pii pair<int,int>

vector<pii> eclist[MAX];//[[index,cost]]

void bfs(int start,int n){
    queue<int> q; // index
    vector<bool> visited(n, false);
    q.push(start);
    while (!q.empty()){
        int u = q.front();q.pop();
        visited[u] = true;
        for (pii vpair : eclist[u]) {
            int v = vpair.first;
            if(!visited[v]){
                q.push(v);
            }
        }
    }
}

void dijkstra_print_distance(int start, int n){
    priority_queue<pii> q; // cost,index
    vector<int> costs(n,INF);
    vector<bool> visited(n, false);
    costs[0] = 0;
    q.push(make_pair(0, start));
    while (!q.empty()){
        pii upair = q.top();q.pop();
        int u = upair.second,ucost = upair.first * -1;
        visited[u] = true;
        if( costs[u] < ucost) {
            continue;
        }
        for (pii vpair : eclist[u]) {
            int v = vpair.first,vcost = vpair.second;
            if(visited[v])continue;
            if (costs[v] > costs[u] + vcost){
                costs[v] = costs[u] + vcost;
                q.push(pii(costs[v] * -1, v));
            }
        }
    }
    for (int i = 0; i < n; ++i) cout << i << " " << costs[i] << endl;
}

int main(){
    int n;
    freopen("in", "r", stdin);
    cin >> n;
    for (int i = 0; i < n; ++i) {
        int id,m,v,c;
        cin >> id >> m;
        for (int j = 0; j < m; ++j) {
            cin >> v >> c;
            eclist[id].push_back(pair<int,int>(v,c));
        }
    }

    dijkstra_print_distance(0, n);

    return 0;
}

C++: #include<iostream>
#include<climits>
#include<vector>
#include<queue>
using namespace std;

enum Color{WHITE, GRAY, BLACK};
struct edge{
        int v,c;
        edge(int v, int c): v(v), c(c){}
};
bool operator< (const edge &e, const edge &f){return e.c<f.c;}

int n;
vector<vector<edge>> a;
int *r;

void dijkstra(){
        Color color[n];
        for(int i=0;i<n;i++) color[i]=WHITE;
        color[0] = GRAY;
        priority_queue<edge> pq;
        pq.push(edge(0,0));
        while(!pq.empty()){
                edge e = pq.top(); pq.pop();
                if(color[e.v]==BLACK) continue;
                color[e.v] = BLACK;
                r[e.v] = - e.c;

                for(int i=0;i<a[e.v].size();i++){
                        edge f = a[e.v][i];
                        if(color[f.v]==BLACK) continue;
                        color[f.v] = GRAY;
                        int cost = e.c - f.c;
                        pq.push(edge(f.v, cost));
                }
        }

}

int main(){
        int u,k,v,c;
        cin>>n;
        a = vector<vector<edge>>(n);
        r = new int [n];
        for(int i=0;i<n;i++){
                cin>>u>>k;
                for(int j=0;j<k;j++){
                        cin>>v>>c;
                        a[u].emplace_back(edge(v,c));
                }
        }

        dijkstra();

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

C++: #include<iostream>
#include<algorithm>
#include<queue>
using namespace std;
static const int MAX = 10000;
static const int INFTY = (1 << 20);
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() {
	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[v] + adj[u][j].second) {
				d[v] = d[u] + adj[u][j].second;
				PQ.push(make_pair(d[v] * (-1), v));
				color[v] = GRAY;
			}
		}
	}

	for (int i = 0; i < n; i++) {
		cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << endl;
	}
}

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

	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			cin >> v >> c;
			adj[u].push_back(make_pair(v, c));
		}
	}

	dijkstra();

	return 0;
}