Go: // ダイクストラのアルゴリズム
package main

import (
	"bufio"
	"fmt"
	"log"
	"math"
	"os"
	"strconv"
	"strings"
)

type color int

const (
	white color = iota // 未訪問
	mst                // MSTとして確定
)

// 頂点
type node struct {
	num       int         // 頂点の番号
	weights   map[int]int // 重みMAP
	parent    *node       // MSTへの重み最小の親
	distFromS int         // 始点からの距離
	color     color
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	n := eGetInt(scanner)

	nodes := make([]*node, n)
	for i := 0; i < n; i++ {
		weights := eAtoi((strings.Fields(eGetline(scanner))))
		v := &node{weights[0], make(map[int]int, weights[1]), nil, math.MaxInt32, white}
		for j := 0; j < weights[1]; j++ {
			k := weights[j*2+2] // 相手の頂点名
			w := weights[j*2+3] // 重み
			v.weights[k] = w
		}
		nodes[i] = v
	}

	// 初回はnode[0]がMSTに入るように
	nodes[0].distFromS = 0

	for { // 全部チェックするまで

		// どの頂点を新たにMSTに取り込むか

		var minNode *node
		min := math.MaxInt32
		for _, v := range nodes {
			if v.color == mst {
				continue
			}
			if v.distFromS < min {
				min = v.distFromS
				minNode = v
			}
		}
		if minNode == nil {
			// すべて完了している.
			break
		}

		// MSTに追加する頂点決定
		minNode.color = mst

		// fmt.Printf(">[%v]\n", minNode)
		// MSTに属していない頂点それぞれについて,Startからの最小の重みの距離を更新
		for i, v := range nodes {
			if v.color == mst {
				continue
			}
			w, ok := minNode.weights[i]
			if !ok {
				// minNodeと接してない
				continue
			}

			if minNode.distFromS+w < v.distFromS {
				// minNode経由の距離がもっとも重みが少ないので親を変更
				v.distFromS = minNode.distFromS + w
				v.parent = minNode
				// fmt.Printf("[%v %v]\n", v, minNode)
			}
		}
		// fmt.Printf("<\n")
	}

	for i, v := range nodes {
		fmt.Printf("%d %d\n", i, v.distFromS)
	}
}

func eGetInt(scanner *bufio.Scanner) int {
	t := eAtoi(strings.Fields(eGetline(scanner)))
	return t[0]
}

func eGetline(p *bufio.Scanner) string {
	if !p.Scan() {
		if err := p.Err(); err != nil {
			log.Fatal(err.Error())
		}
		return ""
	}
	return p.Text()
}

func eAtoi(s []string) []int {
	ints := make([]int, len(s))
	var err error
	for i, e := range s {
		ints[i], err = strconv.Atoi(e)
		if err != nil {
			log.Fatal(err.Error())
		}
	}
	return ints
}

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

typedef long long ll;

struct Edge {
    ll t,w;
};

struct State {
    ll v;
    ll score;
    bool operator < (const State& tgt) const {
	return score > tgt.score;
    }
};

vector<ll> dijkstra(vector<vector<Edge>>& G, const int start) {
    const ll V = G.size();

    vector<ll>res(V,INT_MAX);
    priority_queue<State> q;
    q.push( State{0,0} );
    while( q.size() ) {
	State s = q.top(); q.pop();
	if( res[s.v] != INT_MAX ) continue;
	res[s.v] = s.score;
	for(auto& e : G[s.v]) {
	    if( res[e.t] != INT_MAX ) continue;
	    q.push( State{e.t, s.score + e.w} );
	}
    }
    return res;
}


int main () {

    ll V; cin >> V;
    vector<vector<Edge>> G(V);
    for(int i=0; i<V; i++) {
	ll u,k; cin >> u >> k;
	for(int j=0; j<k; j++) {
	    ll v,w; cin >> v >> w;
	    G[i].push_back( Edge{v,w} );
	}
    }
    vector<ll> res = dijkstra(G,0);
    for(int i=0; i<V; i++) {
	cout << V << " " << res[i] << endl;
    }    
    return 0;
}

C++: #include<iostream>
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 (1) {
		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() {
	cin >> 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++) {
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			cin >> v >> c;
			M[u][v] = c;
		}
	}

	dijkstra();

	return 0;
}

C++: #include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <bitset>
#include <cstring>
#include <deque>
#include <iomanip>
#include <limits>
#include <fstream>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
#define CLR(mat) memset(mat, 0, sizeof(mat))
typedef long long ll;
const int inf = 1e9;
// ダイクストラO(elogv)
struct edge{
  int to, cost;
  edge(int t, int c) {
    to = t, cost = c;
  }
};
typedef pair<int, int> P;
int N;
vector<edge> G[111];
int d[111];
void dijkstra(int s){
  priority_queue<P, vector<P>, greater<P> >que;
  FOR(i,1,N+1) d[i] = inf;
  d[s] = 0;
  que.push(P(0, s));
  while(!que.empty()){
    P p = que.top(); que.pop();
    int v = p.second;
    if(d[v] < p.first) continue;
    for(auto &e : G[v]){
      if(d[e.to] > d[v] + e.cost){
        d[e.to] = d[v] + e.cost;
        que.push(P(d[e.to], e.to));
      }
    }
  }
}
int main()
{
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin>>N;
  FOR(i,0,N){
    int u, k;
    cin >> u >> k;
    FOR(j,0,k){
      int v, c;
      cin >> v >> c;
      G[u].push_back(edge(v, c));
    }
  }
  dijkstra(0);
  FOR(i,0,N){
    cout << i << " " << d[i] << endl;
  }
}

C++: #include "bits/stdc++.h"
#include <unordered_set>

#define _CRT_SECURE_NO_WARNINGS

#define REP(i, n) for(decltype(n) i = 0; i < (n); i++)
#define REP2(i, x, n) for(decltype(x) i = (x); i < (n); i++)
#define REP3(i, x, n) for(decltype(x) i = (x); i <= (n); i++)
#define RREP(i, n) for (decltype(n) i = (n) - 1; i >= 0; i--)

#define ALL(a) (a).begin(),(a).end()
#define SORT(c) sort((c).begin(),(c).end())
#define DESCSORT(c) sort(c.begin(), c.end(), greater<int>())

using namespace std;

const int INF = 1000000000;
const double PI = 3.1415926535897932384626433832795;

// N, E, S, W
const int dx[4] = { 1, 0, -1, 0};
const int dy[4] = { 0, 1, 0, -1};

using LL = long long int;
using LD = long double;
using pii = pair<int, int>;
using pll = pair<LL, LL>;
using pdd = pair<double, double>;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vl = vector<LL>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vd = vector<double>;
using vs = vector<string>;

//==============================================
int n;
vi color, D;
vvi M;

void print() {
	REP(i, n) {
		cout << i << " " << D[i] << "\n";
	}
}

void solve() {
	D[0] = 0;

	while (true) {
		int u = -1;
		int minV = INF;

		REP(i, n) {
			if (color[i] != 2 && minV > D[i]) {
				u = i;
				minV = D[i];
			}
		}

		if (u == -1) break;

		color[u] = 2;

		REP(i, n) {
			if (color[i] != 2 && M[u][i] != INF && D[u] + M[u][i] < D[i]) {
				D[i] = D[u] + M[u][i];
				color[i] = 1;
			}
		}
	}

	print();
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);

	cin >> n;
	color.resize(n);
	D.resize(n, INF);
	M.resize(n, vi(n, INF));

	int u, k, c, v;
	REP(i, n) {
		cin >> u >> k;
		REP(j, k) {
			cin >> c >> v;
			M[u][c] = v;
		}
	}

	solve();
	return 0;
}