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()

	route := make([][]Node, n)
	weight := make([]int, n)
	for i := 0; i < n; i++ {
		weight[i] = NIL
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		route[i] = make([]Node, k)
		for j := 0; j < k; j++ {
			route[u][j] = Node{id: scanInt(), weight: scanInt()}
		}
	}

	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 _, nextNode := range route[node.id] {
			if weight[nextNode.id] != NIL {
				continue
			}
			nextNode.weight += node.weight
			heap.Push(h, nextNode)
		}
	}

	for i, w := range weight {
		fmt.Println(i, w)
	}
}

C++: /////////////////////////////////////////////////////////
//
//  c/temp.cpp file
//  Last Updated: 2018-10-23 ...Maybe
//
//    I hope you adding this code to the setting file
//    alias g++='g++ -std=c++1y -DDEBUG_LOCAL'
//
/////////////////////////////////////////////////////////

#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define mp make_pair
#define pb push_back

//#define int long long

#define _overload3(_1,_2,_3,name,...) name
#define _REP(i,n) REAP(i,0,n)
#define REAP(i,a,b) for(int i=int(a);i<int(b);++i)
#define REP(...) _overload3(__VA_ARGS__,REAP,_REP,)(__VA_ARGS__)

#define _REPR(i,n) REAPR(i,n,0)
#define REAPR(i,a,b) for(int i=int(a-1);i>=int(b);--i)
#define REPR(...) _overload3(__VA_ARGS__,REAPR,_REPR,)(__VA_ARGS__)

#define ALL(a) a.begin(),a.end()
#define rALL(a) a.rbegin(),a.rend()

#define coutALL(a) {int loop_coutALL=0;for(auto e:a) cout<<(loop_coutALL++?" ":"")<<e; cout<<endl;}

#define coutYN(a) cout<<((a)?"YES":"NO")<<endl;
#define coutYn(a) cout<<((a)?"Yes":"No")<<endl;
#define coutyn(a) cout<<((a)?"yes":"no")<<endl;

#define pcnt __builtin_popcount
#define buli(x) __builtin_popcountll(x)

const int INF=1145141919;
//const long long INF=114514191911451419;
const int MOD=(int)1e9+7;
const double EPS=1e-12;
const int dx[]={1,0,-1,0},dy[]={0,1,0,-1};
//const int dx[]={-1,-1,-1,0,1,1,1,0},dy[]={-1,0,1,1,1,0,-1,-1};

using vi=vector<int>;
using vvi=vector<vi>;
using vs=vector<string>;

typedef pair<int,int> pii;
typedef pair<int,string> pis;
typedef pair<string,int> psi;
typedef pair<string,string> pss;

typedef long long ll;

template<typename T> istream &operator >> (istream &is, vector<T> &v){for(T &x:v) is>>x;return is;}
template<typename T> ostream &operator << (ostream &os, vector<T> &v){int i=0;for(T &x:v) os<<(i++?" ":"")<<x;return os;}

ll rev(ll n){ll x=0;for(;n>0;){x=x*10+n%10;n/=10;}return x;}

ll upper(ll n,ll m){return (n+m-1)/m;};
ll rounding(ll n){return (long double)n+0.5;};

bool inG(ll x,ll n){return 0<=x && x<n;}
bool outG(ll x,ll n){return x<0 || n<=x;}

inline int qp(int a,ll b){if(!b)return 1;int ans=1;do{if(b&1)ans=1ll*ans*a;a=1ll*a*a;}while(b>>=1);return ans;}
inline int qp(int a,ll b,int mo){if(!b)return 1;int ans=1;do{if(b&1)ans=1ll*ans*a%mo;a=1ll*a*a%mo;}while(b>>=1);return ans;}

inline ll fac(ll k,ll n){ll a=1;for(int i=0;i<n;i++)a*=k--;return a;}
inline ll fac(ll k,ll n,int mo){ll a=1;for(int i=0;i<n;i++)a*=k--,a%=mo;return a;}

inline int dsum(ll n){int a=0;for(;n;n/=10)a+=n%10;return a;}

struct Arithmetic{Arithmetic(){cin.tie(0);ios::sync_with_stdio(0);cout<<fixed<<setprecision(20);}};

//#define DEBUG_LOCAL

#ifdef DEBUG_LOCAL
template<typename T> void deb(T a){cerr<<"deb: "<<a<<"です"<<endl;}
#define debl {cerr<<"debug: "<<__LINE__<<"行目だ"<<endl;}
void what_cr(){cout<<__GCC_ATOMIC_CHAR16_T_LOCK_FREE<<" ←？"<<endl;}
//ori_func S

//ori_func E
#else
template<typename T>void deb(T a){}
#define debl
void what_cr(){}void t_t(){}
#endif

int d[10000];
vector <pii> g[10000];

//fiがコスト、seが場所

void dijk(int V,int s){

  priority_queue <pii,vector<pii>,greater<pii> > que;
  fill(d,d+V,INF);

  d[s]=0;

  que.push(pii(0,s));

  for(;!que.empty();){

    pii p=que.top(); que.pop();
    int v=p.se;

    if (d[v]<p.fi) continue;

    for(int i=0;i<(int)g[v].size();i++){

      pii e=g[v][i];

      if(d[e.fi]>d[v]+e.se){

	       d[e.fi]=d[v]+e.se;
	       que.push(pii(d[e.fi],e.fi));

      }
    }
  }
}

signed main(){

  Arithmetic Exception;

  int n;

  cin>>n;

  assert(1 <= n && n <= 10000);

  int edgeCnt=0;

  REP(i,n){

    int u,k;
    cin>>u>>k;

    REP(j,k){

      int c,v;
      cin>>c>>v;

      assert(0 <= c && c <= 100000);

      g[u].pb(mp(c,v));

      edgeCnt++;

    }

  }

  dijk(n,0);

  REP(i,n){

    assert(d[i] != INF);
    cout<<i<<" "<<d[i]<<endl;

  }

  return 0;

}

C++: #include <stdio.h>
#include <vector>
#include <utility>
#define rep(i, n) for(int i = 0; i < n; ++i)
using namespace std;

typedef long long ll;

int main(void) {
  int n, now = 0;
  scanf("%d", &n);
  ll dis[n];
  rep(i, n) dis[i] = 10e13;
  dis[0] = 0;
  char f[n];
  rep(i, n) f[i] = 0;
  f[0] = 1;
  vector< pair<int, int> > vec[n];
  rep(i, n) {
    int u, k;
    scanf("%d%d", &u, &k);
    rep(j, k) {
      int c, v;
      scanf("%d%d", &v, &c);
      pair<int, int> p = make_pair(v, c);
      vec[u].push_back(p);
    }
  }
  /*rep(i, n) {
    vector< pair<int, int> >::iterator it;
    for(it = vec[i].begin(); it != vec[i].end(); ++it) printf("%d:%d ", (*it).first, (*it).second);
    printf("\n");
  }*/
  rep(i, n - 1) {
    int j = now;
    vector< pair<int, int> >::iterator it;
    for(it = vec[j].begin(); it != vec[j].end(); ++it) {
      if(dis[(*it).first] > dis[j] + (*it).second) dis[(*it).first] = dis[j] + (*it).second;
    }
    ll min = 10e13, minn;
    rep(k, n) if(!f[k] && min > dis[k]) min = dis[k], minn = k;
    f[minn] = 1;
    now = minn;
    /*rep(j, n) printf("%d ", dis[j]);
    printf("\n");*/
  }
  rep(i, n) printf("%d %lld\n", i, dis[i]);
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <queue>
#include <climits>
using namespace std;
static const int WHITE=0;
static const int GRAY=1;
static const int BLACK=2;
static const int MAX=10000;

int n;
vector<pair<int,int> >A[MAX];

void dijkstra(){
  priority_queue<pair<int,int> > PQ; 
  int color[MAX],d[MAX],u;
  for(int i=0;i<n;i++){
    color[i]=WHITE;
    d[i]=INT_MAX;
  }
  d[0]=0;
  PQ.push(make_pair(0,0));
  color[0]=GRAY;

  while(!PQ.empty()){
    pair<int,int> f=PQ.top();
    PQ.pop();
    u=f.second;
    color[u]=BLACK;
    if(d[u]<f.first*(-1)) continue;

    for(int v=0;v<A[u].size();v++){
      int k=A[u][v].first;
      if(color[k]!=BLACK){
	if(d[u]+A[u][v].second<d[k]){
	  d[k]=d[u]+A[u][v].second;
	  color[k]=GRAY;
	  PQ.push(make_pair(d[k]*(-1),k));
	}
      }
    }
  }
  for(int i=0;i<n;i++){
    cout<<i<<" "<<(d[i]==INT_MAX ? -1:d[i])<<endl;
  }
}


int main(){
  int k,u,v,c;

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

  return 0;
}