Go: package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := make(map[int]int)
	q[0] = 0
	visited := make(map[int]struct{})
	out := make([]int, n)

	for len(q) > 0 {
		u := top(q)
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			if d, ok := q[uu]; !ok || d > q[u]+c {
				q[uu] = q[u] + c
			}
		}

		out[u] = q[u]
		delete(q, u)
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

func top(q map[int]int) int {
	minu := -1
	min := -1
	for u, d := range q {
		if min < 0 || d < min {
			minu = u
			min = d
		}
	}

	return minu
}

C++: // ダイクストラ法
// Dijkstra's Algorithm
// Single Source Shortest Path 1 単一始点最短経路
#include <iostream>
#include <cstring>
#include <algorithm>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <vector>
using namespace std;

static const int MAX = 100;
static const int INF = (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] = INF;
        color[i] = WHITE;
    }

    d[0] = 0;
    color[0] = GRAY;

    while (true) {
        minv = INF;
        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] != INF) {
                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] == INF ? -1 : d[i]) << endl;
    }
}

int main() {

    cin >> n;

    for(int i = 0; i < n; i++) {
        for(int j = 0; j < n; j++) {
            M[i][j] = INF;
        }
    }

    int k, c, u, v;

    for(int i = 0; i < n; i++) {
        cin >> u >> k;
        for(int j = 0; j < k; j++) {
            cin >> v >> c;
            M[u][v] = c;
        }
    }

    dijkstra();

    return 0;
}

C++: #include "bits/stdc++.h"
using namespace std;
static const int MAX=10000;
static const int INFTY=(1<<21);
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;

int n;
//????????????????????°???????????£??\???????????¨???
vector<pair<int,int> >adj[MAX];

void dijkstra(){
	priority_queue<pair<int,int> > PQ;
	int color[MAX];
	int d[MAX];
	for (int i = 0; i < n; ++i) {
		d[i]=INFTY;
		color[i]=WHITE;
	}
	d[0]=0;
	PQ.push(make_pair(0,0));
	color[0]=GRAY;
	while(!PQ.empty()){
		pair<int,int> f=PQ.top();PQ.pop();
		int u=f.second;
		color[u]=BLACK;
		//????°???????????????????????????????????????§???????????°??????
		if(d[u]<f.first *(-1))continue;

		for (int j = 0; j < adj[u].size(); ++j) {
			int v=adj[u][j].first;
			if(color[v]==BLACK)continue;
			if(d[v]>d[u]+adj[u][j].second){
				d[v]=d[u]+adj[u][j].second;
				//priority_queue????????????????????§??§??????????????????????????????-1????????????
				PQ.push(make_pair(d[v]*(-1),v));
				color[v]=GRAY;
			}
		}
	}
	for (int i = 0; i < n; ++i) {
		cout<<i<< " "<<(d[i]==INFTY?-1:d[i])<<endl;
   }
}


int main(){
	cin>>n;
	int k,c,u,v;
	for (int i = 0; i < n; ++i) {
		cin>>u>>k;
		for (int j = 0; j < k; ++j) {
			cin>>v>>c;
			adj[u].push_back(make_pair(v,c));
		}
	}
	dijkstra();
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> P;
constexpr int di[] = {0, 1, 0, -1}, dj[] = {1, 0, -1, 0};
#define rep(i, n) for (int i = 0; i < n; i++)
#define repr(i, n) for (int i = n; i >= 0; i--)
#define sort(v) sort((v).begin(), (v).end())
#define sortr(v) sort((v).rbegin(), (v).rend())
#define all(v) (v).begin(), (v).end()
#define max 100005
#define nil -1
constexpr int inf = 100000000;

struct edge{
    int from,to,cost;
};

vector<edge> es;
vector<int> d;
int n;

void be(int s){
    d.resize(max);
   fill(d.begin(),d.end(),inf);
   d[s]=0;
   while(true){
       bool update=false;
       for(int i=0;i<es.size();i++){
           edge e=es[i];
           if(d[e.from]!=inf&&d[e.from]+e.cost<d[e.to]){
               d[e.to]=d[e.from]+e.cost;
               update=true;
           }
       }
       if(!update){
           break;
       }
   }
}

int main() {
  int  u,k,v,c;
  cin>>n;
    d.resize(n);
  rep(i,n){
      cin>>u>>k;
      for(int j=0;j<k;j++){
          cin>>v>>c;
          es.push_back({u,v,c});
        }
    }
    be(0);
    rep(i,n){
        cout<<i<<" "<<d[i]<<endl;
    }
  return 0;
}

C++: #include <cstdio>

const int N = 100;
const int INF = 100001;
int cost[N][N];
int minCost[N] = {0};
bool isDecide[N] = {false};

int getMinIndex(int n) {
        int minIndex = -1;
        int cost = INF;
        for (int i = 0; i < n; i++) {
                if (minCost[i] < cost && !isDecide[i]) {
                        cost = minCost[i];
                        minIndex = i;
                }
        }

        return minIndex;
}

int main() {
        for (int i = 0; i < N; i++) {
                for (int j = 0; j < N; j++) {
                        cost[i][j] = -1;
                }
        }
        for (int i = 1; i < N; i++) {
                minCost[i] = INF;
        }
        int n, u, k, v, c;

        scanf("%d", &n);
        for (int i = 0; i < n; i++) {
                scanf("%d %d", &u, &k);
                for (int j = 0; j < k; j++) {
                        scanf("%d %d", &v, &c);
                        cost[u][v] = c;
                }
        }
        while (true) {
                int from = getMinIndex(n);
                if (from < 0) {
                        break;
                }
                isDecide[from] = true;
                for (int to = 0; to < n; to++) {
                        if (cost[from][to] < 0 || isDecide[to]) {
                                continue;
                        }
                        int newCost = minCost[from] + cost[from][to];
                        if (newCost < minCost[to]) {
                                minCost[to] = newCost;
                        }
                }
        }
        for (int i = 0; i < n; i++) {
                printf("%d %d\n", i, minCost[i]);
        }

        return 0;
}