Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
const INF = 1 << 60

type Edge struct {
	to, cost int
}

type Node struct {
	id, cost int
}

type PQ []Node

func (pq PQ) Len() int           { return len(pq) }
func (pq PQ) Less(i, j int) bool { return pq[i].cost < pq[j].cost }
func (pq PQ) Swap(i, j int)      { pq[i], pq[j] = pq[j], pq[i] }

func (pq *PQ) Push(x interface{}) {
	*pq = append(*pq, x.(Node))
}

func (pq *PQ) Pop() interface{} {
	old := *pq
	n := len(old)
	x := old[n-1]
	*pq = old[0 : n-1]
	return x
}

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		E[id] = make([]Edge, k)
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id][j] = Edge{to, cost}
		}
	}

	d := make([]int, N)
	for i := 0; i < N; i++ {
		d[i] = INF
	}
	done := make([]bool, N)
	pq := &PQ{}
	heap.Init(pq)
	d[0] = 0
	heap.Push(pq, Node{0, 0})
	for pq.Len() > 0 {
		cur := heap.Pop(pq).(Node).id
		if done[cur] {
			continue
		}
		done[cur] = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+d[cur]
			if !done[to] && cost < d[to] {
				d[to] = cost
				heap.Push(pq, Node{to, cost})
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, d[i])
	}
	wtr.Flush()
}

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;
}