Go: package main

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

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}
func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}
func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}
func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 // for safety
	*pq = old[0 : n-1]
	return item
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

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

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

		out[u] = d
		visited[u] = struct{}{}
	}

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

C++: #include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define sz(x) int(x.size())
#define ALL(c) (c).begin(), (c).end()
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v, x) (std::find(v.begin(), v.end(), x) != v.end())

using namespace std;
typedef long long ll;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
const int INF = 1001001001;
const long long INFL = (1LL<<60);
const double eps = (1e-9);

typedef pair<int, int> P;

// @param [in] n: ノード数
// @param [in] cost: 重みの隣接表現
// @param [in] s: スタートするノード
// @param [out] d: s からの距離
void dijkstra(const int& n, const vector<vector<pair<int, int>>>& cost, const int& s, vector<int>& d) {
  priority_queue<P, vector<P>, greater<P>> que;  // P#first が小さい順に取り出せる
  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 (int j = 0; j < cost[v].size(); j++) {  // v から移動できる全ての node について
      int t = cost[v][j].first;
      int c = cost[v][j].second;
      if (d[t] > d[v] + c) {
        d[t] = d[v] + c;
        que.push(P(d[t], t));
      }
    }
  }
}

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

  int n;
  cin >> n;
  vector<vector<pair<int, int>>> cost(n);

  rep(i, n) {
    int u, k;
    cin >> u >> k;
    vector<pair<int, int>> tmp(k);
    rep(j, k) {
      int v, c;
      cin >> v >> c;
      tmp[j] = make_pair(v, c);
    }
    cost[i] = tmp;
  }

  // 求めるのは 0 からの距離
  vector<int> d(n, INF);
  dijkstra(n, cost, 0, d);

  rep(i, n) {
    cout << i << " " << d[i] << endl;
  }

  return 0;
}

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

#define REP(i, n) for(int i=0;i<(int)(n);i++)
#define ALL(x) (x).begin(),(x).end()
const int INF = 1e9;

using namespace std;
int n;
int res = 0;
struct node {
    int id;
    int dist;
    bool searched;
};

node v[100];
int edge[100][100];

int main() {
    cin >> n;
    REP(i, n) {
        int u, k;
        cin >> u >> k;
        v[u].id = u;
        v[u].dist = INF;
        v[u].searched = false;
        REP(j, n) edge[i][j] = INF;
        REP(j, k){
            int to, cost;
            cin >> to >> cost;
            edge[i][to] = cost;
        }
    }
    v[0].dist = 0;
    int prev = 0;
    REP(i, n){
        int minimum = INF;
        REP(j, n){
            if(!v[j].searched && minimum >= v[j].dist){
                prev = j;
                minimum = v[j].dist;
            }
        }
        REP(j, n){
            if(!v[j].searched && edge[prev][j] != INF){
                v[j].dist = min(v[j].dist, v[prev].dist + edge[prev][j]);
            }
        }
        v[prev].searched = true;
    }
    REP(i, n) cout << i << " " << v[i].dist << endl;
    return 0;
}

C++: #include <map>
#include <vector>
#include <cstdio>
using namespace std;
int main(){
	int n=0,N,i,j,k,c;
	scanf("%d",&N);
	vector<map<int,int> >dist(N);
	vector<bool>used(N);
	vector<int>cost(N);
	for(;n<N;n++){
		cost[n]=1e9;
		for(scanf("%d%d",&i,&k);k--;dist[i][j]=c)scanf("%d%d",&j,&c);
	}
	for(cost[0]=0;;){ //dijkstra
		int m=1e9;
		for(i=0;i<N;i++)if(!used[i]&&m>cost[i])m=cost[i];
		if(m==1e9)break;
		for(j=0;j<N;j++)if(m==cost[j]){
			map<int,int>::iterator it=dist[j].begin();
			for(used[j]=1;it!=dist[j].end();it++)if(cost[it->first]>it->second+cost[j])cost[it->first]=it->second+cost[j];
		}
	}
	for(i=0;i<n;i++)printf("%d %d\n",i,cost[i]);
}

C++: #include <utility>
#include <string>
#include <vector>
#include <algorithm>
#include <iostream>
using namespace std;

int n;						//えぬ
int a[10000][10000] = {0};	//辺の重さ
bool f[10000];				//その頂点が調査済みかどうか

int main(){
	cin >> n;
	//まず辺の重さをaに入れる
	for ( int i = 0; i < n; i++ ) {
		for ( int j = 0; j < n; j++ ) {
			a[i][j] = -1;
		}
		f[i] = false;
	}
	a[0][0] = 0;
	for ( int i = 0; i < n; i++ ) {
		int u;
		cin >> u;
		int k;
		cin >> k;
		for ( int j = 0; j < k; j++ ) {
			int v;
			cin >> v;
			cin >> a[u][v];
		}
	}
	for ( int i = 0; i < n - 1; i++ ) {
		int k = -1;
		int v = 0;
		for ( int j = 1; j < n; j++ ) {
			if ( a[0][j] == -1 || f[j] ) continue;
			if ( k == -1 || a[0][j] < k ) {
				v = j;
				k = a[0][j];
			}
		}
		f[v] = true;
		for ( int j = 1; j < n; j++ ) {
			if ( v == j ) continue;
			if ( a[v][j] == -1 || f[j] ) continue;
			if ( a[0][j] == -1 || a[0][j] > a[0][v] + a[v][j] ) {
				a[0][j] = a[0][v] + a[v][j];
			}
		}
	}
	for ( int i = 0; i < n; i++ ) {
		cout << i << " " << a[0][i] << endl;
	}
	return 0;
}

C++: #include<iostream>
using namespace std;
#include<queue>
#include<vector>
#include<string>
#include<string.h>
#include<algorithm>
bool b[2003];

#define REP(i, a) for(int i=0;i<a;i++)
	int N=10000000;
int main()
{
	pair<int,int> f;
	vector < pair<int,int> > A[10001];
	priority_queue < pair < int,int > > PQ;
	int min,b,a,k,m,n ,e,p[101],d[101],u,v; //u ?????????v????????¨
	bool color[10001];

	cin>>n;
	REP(i, n) {
		cin>>u>>k;
		REP(i, k) {
			cin>>a>>b;
			if(b==-1) b=N;
			A[u].push_back(make_pair(a,b));
		}
		color[i]=0;
		d[i]=N;
	}
	a=0;
	d[0]=0;
	PQ.push(make_pair(0,0));
	while(!PQ.empty()){
		f=PQ.top();
		PQ.pop();
		u=f.second;
		color[u]=1;
		REP(i,A[u].size()){
			v=A[u][i].first;
			if(color[v]==1){
			continue;
			}
				if(d[v]>A[u][i].second+d[u]){
					d[v]=A[u][i].second+d[u];
					PQ.push(make_pair(d[v]*-1,v));
				}
		}
	}
	REP(i,n){
		cout<<i<<" "<<(d[i] == N ? -1 : d[i])<<endl;
	
	}
	return 0;
}