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>
#include <algorithm>

using namespace std;

typedef pair<int,int> PII;
#define INF 1001001001
#define rep(i,n) for(int i=0; i<n; ++i)
#define mp make_pair

struct edge{
    short to;
    short cost;
    edge(short to,short cost):to(to),cost(cost){}
};

int V;
vector<edge> G[10000];
int d[10000];

void dijkstra(int s){
    priority_queue<PII, vector<PII>, greater<PII>> Q;
    fill(d,d+V,INF);
    d[s]=0;
    Q.push(mp(0,s));

    while(!Q.empty()){
        PII p=Q.top();Q.pop();
        int v=p.second;
        if(d[v]<p.first) continue;
        rep(i,G[v].size()){
            edge e=G[v][i];
            if(d[e.to]>d[v]+e.cost){
                d[e.to]=d[v]+e.cost;
                Q.push(mp(d[e.to],e.to));
            }
        }
    }
}
int n;
int main(){
    cin>>V;
    rep(i,V){
        rep(j,V){
            int u,k;
            cin>>u>>k;
            rep(t,k){
                int v, c;
                cin>>v>>c;
                G[u].push_back(edge(v,c));
            }
        }
    }
    dijkstra(0);
    rep(i,V){
        cout<<i<<" "<<d[i]<<endl;
    }
    return 0;
}

C++: #include <algorithm>
#include <iostream>
#include <queue>
#include <cstdio>
using namespace std;

static const int Max = 100;
static const int Inf = (1<<20);
enum State {
	Not_Searched = 0,
	Connected = 1,
	Searched = 2
};

struct Node {
	int idx;
	int cost;
	Node(int i, int c):	idx(i),	cost(c)	{}
};

int n = 0;
//vector<pair<int,int> > adj[Max]; // pair<??£??\??????index, ??????cost> 
vector <vector<pair<int, int> > >adj; // pair<??£??\??????index, ??????cost>
//vector<Node> adj[Max];

void dijkstra() {
	priority_queue<pair<int, int> > pq; // pair<start ???????????????????????????????????§????????????????´???????idx>
	int st[Max];
	int min_cost[Max];
	for (int i = 0; i < n; i++) {
		st[i] = Not_Searched;
		min_cost[i] = Inf;
	}

	min_cost[0] = 0;
	pq.push(make_pair(0, 0));
	st[0] = Connected;

	while (!pq.empty()) {
		pair<int, int> f = pq.top();
		pq.pop();
		int u = f.second;
		st[u] = Searched;

		if (min_cost[u] < f.first * (-1)) continue;

		for (int i = 0; i < adj[u].size(); i++) {
			int adj_u_idx = adj[u][i].first;
			if (st[adj_u_idx] == Searched) continue;
			if (min_cost[adj_u_idx] > min_cost[u] + adj[u][i].second) {
				min_cost[adj_u_idx] = min_cost[u] + adj[u][i].second;
				pq.push(make_pair(min_cost[adj_u_idx]*(-1), adj_u_idx));
				st[adj_u_idx] = Connected;
			}
		}
	}
	for (int i = 0; i < n; i++) {
		printf("%d %d\n", i, (min_cost[i] == Inf ? -1 : min_cost[i]));
		//cout << i << " " << (min_cost[i] == Inf ? -1 : min_cost[i]) << endl;
	}
	return;
}

int main() {
	cin >> n;
	//cout << n << endl;
	int u, k, vi, ci;
	for (int i = 0; i < n; i++) {
		//scanf("%d %d", &u, &k);
		cin >> u >> k;
		vector<pair<int, int> > buf;
		buf.reserve(k);
		for (int j = 0; j < k; j++) {
			//scanf("%d %d", &vi, &ci);
			cin >> vi >> ci;
			buf.push_back(make_pair(vi, ci));
			//adj[u].push_back(make_pair(vi, ci));
            //Node n(vi, ci);
			//adj[u].push_back(n);
		}
		adj.push_back(buf);
	}
	dijkstra();
	return 0;
}