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>
#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace std;
typedef long long ll;

int n;
vector<pair<int, int> > adj[10000];
string color[10000];
int d[10000];
const int INF = 1001001001;
priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > > Q;

void dijkstra(int s){
    rep(i, n){
        color[i] = "WHITE";
        d[i] = INF;
    }
    d[s] = 0;

    Q.push(make_pair(0, s));

    while(!Q.empty()){
        pair<int, int> p = Q.top(); Q.pop();
        int u = p.second;
        color[u] = "BLACK";

        //if(d[u] < p.first) continue;

        for (int i = 0; i < adj[u].size(); i++){
            int v = adj[u][i].second;
            if(color[v] != "BLACK"){
                if(d[u] + adj[u][i].first < d[v]){
                    d[v] = d[u] + adj[u][i].first;
                    color[v] = "GRAY";
                    Q.push(make_pair(d[v], v));
                }
            }
        }
    }
}

int main() {
    cin >> n;
    rep(i, n){
        int u; cin >> u;
        int k; cin >> k;
        rep(j, k){
            int v, c; cin >> v >> c;
            adj[i].push_back(make_pair(c, v));
        }
    }
    dijkstra(0);
    rep(i, n){
        cout << i << " " << d[i]  << endl;
    }

    return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
#include <algorithm>
#include <functional>
#include <utility>
using namespace std;

const int INF = 1 << 29;

struct Edge{
    int to, cost;
};
typedef pair<int, int> P;

int d[10001];

int main()
{
    int n,u,k,v,c;
    
    cin >> n;
    fill(d, d + n, INF);
    vector<Edge> G[10001];
    for(int i = 0; i < n; ++i){
        cin >> u >> k;
        for(int j = 0; j < k; ++j){
            cin >> v >> c;
            Edge e = {v, c};
            G[u].push_back(e);
        }
    }
    
    priority_queue<P, vector<P>, greater<P>> que;
    d[0] = 0;
    que.push(P(0,0));
    
    while(!que.empty()){
        P p = que.top(); que.pop();
        int v = p.second;
        if(d[v] < p.first) continue;
        for(int i = 0; i < G[v].size(); ++i){
            Edge e = G[v][i];
            if(d[e.to] > d[v] + e.cost){
                d[e.to] = d[v] + e.cost;
                que.push(P(d[e.to], e.to));
            }
        }
    }
    
    for(int i = 0; i < n; ++i){
        cout << i << ' ' << d[i] << endl;
    }
    
}

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

const long long MAX_N = 200000;
long long max_mdif, max_pdif, data, c, ans, s[MAX_N];
int main() {

	max_mdif = 0;
	max_pdif = 0;
	c = 0;
	cin >> data;

	for (int i = 0; i < data; ++i) {
		cin >> s[i];
	}

	for (int i = 1; i < data; ++i) {
		if (s[i] > s[i - 1]) {
			max_pdif += s[i] - s[i - 1];
			c++;
		}
	}
	if (c == 0) {
		for (int i = 1; i < data; ++i) {
			if (s[data - i] < s[data - i - 1]) {
				max_mdif = min(s[data - i] - s[data - i - 1], max_mdif);
			}
		}
	}
	if (c > 0) {
		ans = max_pdif;
	} else {
		ans = max_mdif;
	}

	cout << ans << endl;

	return 0;
}

C++: //
//  main.cpp
//  单元最短路径
//
//  Created by 陆昱珉 on 2018/12/26.
//  Copyright © 2018 Lu. All rights reserved.
//

//dijkstra algorithm

#include <stdio.h>
#define INF 999999

int n, k;
int color[10010], d[10010];
int map[10010][10010];

int dijkstra(int s)
{
    for(int i = 0; i < n; i ++)
    {
        d[i] = INF;
    }
    d[s] = 0;
    while(1)
    {
        int min = INF;
        int u = -1;
        for(int i = 0; i < n; i ++)
        {
            if(min > d[i] && color[i] != 1)
            {
                u = i;
                min = d[i];
            }
        }
        if(u == -1)
            break;
        color[u] = 1;//染色，以防后面重复使用
        for(int i = 0; i < n; i ++)
        {
            if(color[i] != 1 && map[u][i] != INF)
                if(d[i] > d[u] + map[u][i])
                    d[i] = d[u] + map[u][i];
        }
    }
    return 0;
}

int main(void)
{
    int x, y, v;
    scanf("%d", &n);
    for(int i = 0; i < n; i ++)
        for(int j = 0; j < n; j ++)
            map[i][j] = INF;
    for(int i = 0; i < n; i ++)
    {
        scanf("%d%d", &x, &k);
        for(int j = 0; j < k; j ++)
        {
            scanf("%d%d", &y, &v);
            map[x][y] = v;
        }
    }
    dijkstra(0);
    
    for(int i = 0; i < n; i ++)
    {
        if(d[i] != INF)
            printf("%d %d", i, d[i]);
        printf("\n");
    }
    return 0;
}