Go: package main

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

const NIL = -1

type Node struct {
	id     int
	weight int
}

func init() {
	sc.Split(bufio.ScanWords)
}

type NodeHeap []Node

func (h NodeHeap) Len() int           { return len(h) }
func (h NodeHeap) Less(i, j int) bool { return h[i].weight < h[j].weight }
func (h NodeHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *NodeHeap) Push(x interface{}) {
	*h = append(*h, x.(Node))
}

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

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()

	list := make([][]int, n)
	weight := make([]int, n)
	for i := range list {
		list[i] = make([]int, n)
		weight[i] = NIL
		for j := range list[i] {
			list[i][j] = NIL
		}
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		for j := 0; j < k; j++ {
			v := scanInt()
			w := scanInt()
			list[u][v] = w
		}
	}

	start := Node{id: 0, weight: 0}
	h := &NodeHeap{start}
	heap.Init(h)

	for h.Len() > 0 {
		node := heap.Pop(h).(Node)
		if weight[node.id] != NIL {
			continue
		}
		weight[node.id] = node.weight

		for i, w := range list[node.id] {
			if w == NIL {
				continue
			}
			heap.Push(h, Node{id: i, weight: w + node.weight})
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		fmt.Fprint(w, i)
		fmt.Fprint(w, " ")
		fmt.Fprint(w, weight[i])
		fmt.Fprintln(w)
	}
	w.Flush()
}

C++: #include <iostream>
#include <cstdio>
#include <set>
#include <vector>
#include <algorithm>
#include <cstring>
using namespace std;
static const int MAX=100;
static const int INFTY=(1<<21);
static const int WHITE=0;
static const int GRAY =1 ;
static const int BLACK =2;

int n,M[MAX][MAX];

void dijkstra()
{
	int minv;
	int d[MAX],color [MAX];
	
	for(int i=0;i<n;i++)
	{
		d[i]=INFTY;
		color[i]=WHITE;
	}
	d[0]=0;
	color[0]=GRAY;
	while(true)
	{
		minv=INFTY;
		int u=-1;
		for(int i=0;i<n;i++)
		{
			if(minv>d[i]&&color[i]!=BLACK)
			{
				u=i;
				minv=d[i];
			}
		}
		if(u==-1) break;
		color[u]=BLACK;
		for(int v=0;v<n;v++)
		{
			if(color[v]!=BLACK&&M[u][v]!=INFTY)
			{
				if(d[v]>d[u]+M[u][v])
				{
					d[v]=d[u]+M[u][v];
					color[v]=GRAY;
				}
			}
		}
	}
	for(int i=0;i<n;i++)
	{
		cout<<i<<" "<<(d[i]==INFTY?-1:d[i])<<endl;
	}
}

int main()
{
	scanf("%d",&n);
	for(int i=0;i<n;i++)
	{
		for(int j=0;j<n;j++)
		{
			M[i][j]=INFTY;
		}
	}
	int k,c,u,v;
	for(int i=0;i<n;i++)
	{
		scanf("%d%d",&u,&k);
		for(int j=0;j<k;j++)
		{
			scanf("%d%d",&v,&c);
			M[u][v]=c;
		}
	}
	dijkstra();
}

C++: #include <iostream>
#include <cstdio>
#pragma warning(disable:4996)
using namespace std;
const int maxn = 100 + 10;
const int maxv = 10000 + 10;
const int INF = 1 << 21;
int n;
int E;
typedef struct{
	int from, to, cost;
}Edge;

Edge e[maxv];
int d[maxn];
void bellman_ford(int s){
	fill(d, d + n, INF);
	d[s] = 0;
	while (true)	{
		bool bUpdate = false;
		for (int i = 0; i<E; i++)	{
			Edge es = e[i];
			if (d[es.from] != INF&&d[es.to]>d[es.from] + es.cost)		{
				d[es.to] = d[es.from] + es.cost;
				bUpdate = true;
			}
		}
		if (!bUpdate) break;
	}
	for (int i = 0; i<n; i++) printf("%d %d\n", i, d[i]);
}

int main(){
	scanf("%d", &n);
	int id, c;
	E = 0;
	for (int i = 0; i<n; i++){
		scanf("%d%d", &id, &c);
		while (c--){
			scanf("%d%d", &e[E].to, &e[E].cost);
			e[E].from = id;
			E++;
		}
	}
	bellman_ford(0);
	return 0;
}

C++: /*宣言*/
#include<cstdio>
#include<iostream>
#include<algorithm>
#include<math.h>
#include<queue>
#include<string.h>
#include<string>
#include<vector>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
int main()
{
	int n, u, k, w[101][101], v, c;
	int d[101], kas[101] = { 0 }, K;
	cin >> n;
	memset(d, 0x7f, sizeof(d));
	memset(w, 0x7f, sizeof(w));
	rep(i, n)
	{
		cin >> u >> k;
		rep(j, k)
		{
			cin >> v >> c;
			w[u][v] = c;
		}
	}
	d[0]=0;
	int p[101];
	int Min,Min1;
	Min = 0;
	Min1 = 0x7f;
	kas[0] = 1;
	rep(j, n)
	{
		rep(i, n)
		{
			if (d[i] > d[Min] + w[Min][i])
			{
				d[i] = d[Min] + w[Min][i];
				p[i] = Min;
			}
			if (Min1 > d[i] && kas[i] == 0)
			{
				Min1 = d[i];
				K = i;
			}
		}
		kas[K] = 1;
		Min = K;
		Min1 = 0x7f;
	}
	rep(i, n)
	{
		cout << i <<' '<< d[i] << endl;
	}
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

static const int N = 100;
static const int inf = (1 << 30);
static const int white = 0;
static const int gray = 1;
static const int black = 2;

int n, M[N][N];

void dijkstra(int s) {
	int color[N], d[N];
	for (int i = 0; i < n; i++) {
		color[i] = white;
		d[i] = inf;
		//p[n] = inf;
	}
	d[s] = 0;
	color[s] = gray;
	int u = -1;
	while (true) {
		int mincost = inf;
		for (int i = 0; i < n; i++) {
			if (color[i] != black && d[i] < mincost) {
				mincost = d[i];
				u = i;
			}
		}
		if (mincost == inf) {
			break;
		}
		color[u] = black;
		for (int v = 0; v < n; v++) {
			if (color[v] != black && M[u][v] != inf) {
				if (d[v] > d[u] + M[u][v]) {
					d[v] = d[u] + M[u][v];
					color[v] = gray;
					//p[v] = u;
				}
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << " " << (d[i] == inf ? -1 : d[i]) << '\n';
	}
	//return  0;
}

int main() {
	int u, k, v, c;
	cin >> n;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			M[i][j] = inf;
		}
	}
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			cin >> v >> c;
			M[u][v] = c;
		}
	}
/*	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (M[i][j] == inf) {
				cout << -1  << " ";
			} else {
				cout << M[i][j] << " ";
			}
		}
		cout << '\n';
}
*/
	dijkstra(0);
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <deque>
#include <queue>
#include <list>
#include <stack>
#include <string>
#include <tuple>
#include <functional>
#include <numeric>
#include <cmath>
#include <iomanip>
#include <map>
#include <random>
#include <cstdlib>
#define INT_MAX 2147483647
#define INT_MIN -2147483646
#define Loop(i, n) for(int i = 0; i < (int)n; i++)
#define Loop1(i, n) for(int i = 1; i <= (int)n; i++)
#define Loopr(i, n) for(int i = (int)n - 1; i >= 0; i--)
#define Loopr1(i, n) for(int i = (int)n; i >= 1; i--)
using namespace std;
typedef long long int ll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;

static const int N = 105;

struct vertex {
	int id;
	int p;
	int d;
	bool operator<(const vertex & another) const {
		return (d != another.d ? d>another.d : id>another.id);
	}
};

struct edge {
	int end;
	int w;
};

int main() {
	int n;
	cin >> n;
	vector<vector<edge>> E(N);
	Loop(i, n) {
		int u, k;
		cin >> u >> k;
		Loop(i, k) {
			int v, c;
			cin >> v >> c;
			E[u].push_back({ v,c });
		}
	}
	//
	priority_queue<vertex> pq;
	vi color(N, 0), dist(N, 0);
	pq.push({ 0,-1,0 });
	while (pq.size() > 0) {
		vertex v = pq.top();
		pq.pop();
		if (color[v.id] == 1) continue;
		dist[v.id] = v.d;
		color[v.id] = 1;
		Loop(j, E[v.id].size()) {
			pq.push({ E[v.id][j].end, v.id, dist[v.id] + E[v.id][j].w });
		}
	}
	Loop(i, n) {
		cout << i << " " << dist[i] << endl;
	}
	return 0;
}