Go: package main

import (
	"strconv"
	"fmt"
	"bufio"
	"os"
)
const INF = 1 << 21
var scanner = bufio.NewScanner(os.Stdin)

func nextInt() int {
	scanner.Scan()
	i, e := strconv.Atoi(scanner.Text())
	if e != nil {
		panic(e)
	}
	return i
}


func main() {
	scanner.Split(bufio.ScanWords)
	n := nextInt()
	adj := make([][]int, n)
	for i := range adj {
		adj[i] = make([]int, n)
	}

	for i := 0;i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			v := nextInt()
			c := nextInt()
			adj[u][v] = c
		}
	}

	// for i := range adj {
	// 	fmt.Println(adj[i])
	// }

	dist := make([]int, n)
	prev := make([]int, n)
	visited := make([]bool, n)
	dijkstra := func(start int, size int) {
		for i := 0; i < size; i++ {
			dist[i] = INF
			prev[i] = -1
			visited[i] = false
		}
		dist[start] = 0
		for {
			u := -1
			tmp_min := INF
			for i := 0; i < size; i++ {
				if visited[i] == false && dist[i] < tmp_min {
					tmp_min = dist[i]
					u = i
				}
			}
			if u == -1 {
				break
			}
			visited[u] = true
			for i := 0; i < size; i++ {
				if adj[u][i] > 0 {
					w := adj[u][i]
					newlen := dist[u] + w
					if newlen < dist[i] {
						dist[i] = newlen
						prev[i] = u
					}
				}
			}
		}
	}
	dijkstra(0, n)
	for i, cost := range dist {
		fmt.Printf("%d %d\n", i, cost)
	}
}

C++: #include <iostream>
using ll = long long;
using namespace std;
/* initialize */
int n, u, k, v, c, A[100][100];

void dijkstra(){
    int c[100], d[100], p[100];
    for (int i = 0; i < n; ++i) { c[i] = 0;  d[i] = 100000000;}
    d[0] = 0;
    p[0] = -1;
    int minc;
    while(true){
        minc = INT32_MAX;
        int u = -1;
        for (int i = 0; i < n; ++i) {
            if (c[i] != 2 && d[i] < minc){
                minc = d[i];
                u = i;
            }
        }
        if(u == -1) break;

        c[u] = 2;

        for (int v = 0; v < n; ++v) {
            if (c[v] != 2 && A[u][v] != 100000000){
                if(d[u] + A[u][v] < d[v]){
                    d[v] = d[u] + A[u][v];
                    p[v] = u;
                    c[v] = 1;
                }
            }
        }
    }
    for (int i = 0; i < n; ++i) {
        cout << i << " " << (d[i] == 100000000 ? -1 : d[i]) << "\n";
    }
};
/* main */
int main() {
    cin >> n;
    for (int l = 0; l < n; ++l) {
        for (int i = 0; i < n; ++i) {
            A[l][i] = 100000000;
        }
    }
    for (int i = 0; i < n; ++i) {
        scanf("%d %d", &u, &k);
        for (int j = 0; j < k; ++j) {
            scanf("%d %d", &v, &c);
            A[u][v] = c;
        }
    }
    dijkstra();
    return 0;
}

C++: #include <iostream>
#include <algorithm>
using namespace std;
#define MAX_N 100
#define INF 1e9

int cost[MAX_N][MAX_N];
int d[MAX_N];
bool used[MAX_N];
int n, u, k, c, v;

void dijkstra(int s){
  fill(d, d + n, INF);
  fill(used, used + n, false);
  d[s] = 0;

  while(true){
    int v = -1;

    for(int u = 0; u < n; u++){
      if(!used[u] && (v == -1 || d[u] < d[v])) v = u;
    }

    if(v == -1) break;
    used[v] = true;

    for(int u = 0; u < n; u++){
      d[u] = min(d[u], d[v] + cost[v][u]);
    }
  }
}

int main(void){
  cin >> n;
  for(int i = 0; i < n; i++){
    for(int j = 0; j < n; j++){
      cost[i][j] = INF;
    }
  }
  for(int i = 0; i < n; i++){
    cin >> u >> k;
    for(int j = 0; j < k; j++){
      cin >> v >> c;
      cost[u][v] = c;
    }
  }
  dijkstra(0);
  for(int i = 0; i < n; i++){
    cout << i << " " << d[i] << endl;
  }
  return 0;
}

C++: #include<cstdio>
#include<queue>
#include<vector>
#define MA 10005
#define INF (1<<30)
using namespace std;
struct Node{
    short id;//根据题意，id最大在short有效范围内
    int weight;
};

short n;
vector<pair<int, int> >adj[MA];//加权有向图的邻接表
priority_queue<Node> PQ;//优先级队列
bool state[MA];//节点状态，false为未访问
int dis[MA];//节点到0点的权值总和

/**重载'<'以自定义优先级队列的优先级，这里定义为权值小优先，与默认的大优先相反*/
bool operator < (const Node node1, const Node node2){
    if(node1.weight==node2.weight)
        return node1.id > node2.id;//权值相同比id，意义不大
    return node1.weight > node2.weight;//返回与正常比较相反的结果
}

/**初始化*/
void init(){
    for(short i=0;i<n;i++)
        dis[i] = INF;//初始权值置为无穷
    dis[0] = 0;//0点权值为0
    Node ini;//0点
    ini.id=0;ini.weight = 0;//0点初始值
    PQ.push(ini);//将0点推入队列
}

/**狄克斯特拉算法*/
void dijkstra(){
    while(!PQ.empty()){//执行至队列为空
        Node nowNode = PQ.top();//从队列中取出元素
        PQ.pop();//清除取出的元素
        short nowId = nowNode.id;//当前元素的ID
        state[nowId] = true;//该节点已从队列中清除，设为访问完毕
        if(dis[nowId]>nowNode.weight)continue;//取出最小值，如果不是最短路径则忽略
        int nowSize = adj[nowId].size();//空间换时间，减少部分运算量
        for(int i=0; i<nowSize; i++){//遍历当前元素的邻接节点
            short nextId = adj[nowId][i].first;//下一个节点的ID
            if(state[nextId]) continue;//如果该节点已被读取则跳过
            int nextWeight = dis[nowId] + adj[nowId][i].second;//0到下一个节点的权值
            if(dis[nextId] > nextWeight){//发现了更短的路径
                dis[nextId] = nextWeight;//更新权值数组对应的数据
                Node nextNode;//即将推入队列的节点
                nextNode.id=nextId; nextNode.weight = nextWeight;//将数据存入节点
                PQ.push(nextNode);//将存有数据的节点推入队列
            }
        }
    }
}

int main(){
    int id, flag, nextId, weight;
    scanf("%d", &n);
    for(int i=0;i<n;i++){
        scanf("%d%d",&id, &flag);
        while(flag--){
            scanf("%d%d", &nextId, &weight);//读取邻接表
            adj[id].push_back(make_pair(nextId, weight));
        }
    }
    init();//执行初始化
    dijkstra();//执行狄克斯特拉算法
    for(short i=0;i<n;i++){//输出全部节点数据
        printf("%d %d\n", i, ((dis[i]==INF)?(-1):(dis[i])));
    }
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
int n;
const int INF=123456789;
const int MAX=100;
int color[MAX];
const int BLACK=2;
const int WHITE=0;
const int GRAY=1;
int d[MAX],M[MAX][MAX];

void ds(){
  int minv,u;

  d[0]=0;color[0]=GRAY;
  while(1){
    minv=INF;u=-1;
    for(int i=0;i<n;i++){
      if(minv>d[i]&&color[i]!=BLACK){
        minv=d[i];
        u=i;
      }
    }

    if(u==-1) break;
    color[u]=BLACK;

    for(int i=0;i<n;i++){
      if(M[u][i]!=INF&&color[i]!=BLACK){
        if(d[i]>d[u]+M[u][i]){
          d[i]=d[u]+M[u][i];
          color[i]=GRAY;
        }
      }
    }
  }
}

int main(){
  int u,k,v,c;
  cin>>n;
  for(int i=0;i<n;i++){
    color[i]=WHITE; d[i]=INF;
    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;
    }
  }

  ds();
  for(int i=0;i<n;i++){
  if(d[i]!=INF)  cout<<i<<" "<<d[i]<<endl;
  else cout<<i<<" "<<-1<<endl;
  }
  return 0;
}

C++: #ifdef LOCAL_BUILD
#include "pch.h"
#define DLOG(msg) cout << "#" << __LINE__ << ":" << msg << endl;
#define DLOG_V(var) \
  cout << "#" << __LINE__ << ":" << #var << " : " << var << endl;
#else
#include <bits/stdc++.h>
#define DLOG(msg)
#define DLOG_V(var)
#endif
using namespace std;

int main() {
  int n;
  cin >> n;
  vector<vector<pair<int, int>>> edges(n, vector<pair<int, int>>());
  for (int i = 0; i < n; ++i) {
    int u, k;
    cin >> u >> k;
    for (int j = 0; j < k; ++j) {
      int v, c;
      cin >> v >> c;
      edges[i].push_back(make_pair(v, c));
    }
  }
  int count = 1;
  constexpr auto not_yet = numeric_limits<int>::max();
  vector<int> costs(n, not_yet);
  costs[0] = 0;
  auto cmp = [](const pair<int, int>& lhs, const pair<int, int>& rhs) {
    return lhs.second > rhs.second;
  };
  priority_queue<pair<int, int>, vector<pair<int, int>>, decltype(cmp)> q(cmp);
  for (auto&& edge : edges[0]) {
    q.push(edge);
  }
  while (true) {
    auto state = q.top();
    q.pop();
    if (costs[state.first] > state.second) {
      assert(costs[state.first] == not_yet);
      for (auto&& edge : edges[state.first]) {
        q.push(make_pair(edge.first, edge.second + state.second));
      }
      costs[state.first] = state.second;
      if (++count == n) {
        break;
      }
    }
  }
  for (int i = 0; i < n; ++i) {
    cout << i << " " << costs[i] << endl;
  }
}