Go: package main

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

const (
	white int = iota
	gray
	black
)

type node struct {
	id     int
	parent int
	edge   []int
	weight []int
	color  int
}

type graph struct {
	nodes    []node
	distance []int
}

var infty = 1 << 32
var null = -1

func constructgraph() *graph {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	n := nextInt(sc)

	g := &graph{make([]node, n), make([]int, n)}

	for i := 0; i < n; i++ {
		id := nextInt(sc)
		edges := nextInt(sc)
		n := node{}
		n.id = id
		n.edge = make([]int, edges)
		n.weight = make([]int, edges)
		n.color = white
		for j := 0; j < edges; j++ {
			to := nextInt(sc)
			w := nextInt(sc)
			n.edge[j] = to
			n.weight[j] = w
		}
		g.nodes[id] = n
	}
	return g
}

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func (g *graph) preparedijkstra(s int) {
	for i := 0; i < len(g.nodes); i++ {
		g.nodes[i].color = white
		g.nodes[i].parent = null
		g.distance[i] = infty
	}
	g.distance[s] = 0
}

func (g *graph) dijkstra(s int) []int {
	g.preparedijkstra(s)

	for {
		var u int
		mincost := infty
		for i, d := range g.distance {
			if g.nodes[i].color != black && mincost > d {
				mincost = d
				u = i
			}
		}

		if mincost == infty {
			break
		}

		g.nodes[u].color = black

		for i, e := range g.nodes[u].edge {
			if g.nodes[e].color != black {
				if g.distance[e] > g.distance[u]+g.nodes[u].weight[i] {
					g.distance[e] = g.distance[u] + g.nodes[u].weight[i]
					g.nodes[e].parent = u
					g.nodes[e].color = gray
				}
			}
		}
	}
	return g.distance
}

func printShortestPath(d []int) {
	for i, v := range d {
		fmt.Printf("%d %d\n", i, v)
	}
}

func main() {
	g := constructgraph()
	d := g.dijkstra(0)
	printShortestPath(d)
}

C++: /*
 ********************************************************************************
 *  Author: ThoseBygones
 *  Version: V1.0
 *  Date: 2018-06-27
 *  Subject: ACM-ICPC
 *  Language: C/C++11
 *  OJ: AOJ
 *  Algorithm: 最短路Dijkstra
 ********************************************************************************
 *  Algo-Description:
 ********************************************************************************
 */

//#include <bits/stdc++.h>  //For CodeForces only

//#pragma comment(linker,"/STACK:102400000,102400000")
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <climits>
#include <ctime>
#include <numeric>
#include <vector>
#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstring>
#include <iomanip>
#include <complex>
#include <deque>
#include <functional>
#include <list>
#include <map>
#include <string>
#include <sstream>
#include <set>
#include <stack>
#include <queue>
using namespace std;
template<class T> inline T sqr(T x)
{
    return x * x;
}
typedef long long LL;
typedef unsigned long long ULL;
typedef long double LD;
typedef pair<int, int> PII;
typedef pair<PII, int> PIII;
typedef pair<LL, LL> PLL;
typedef pair<LL, int> PLI;
typedef pair<LD, LD> PDD;
#define MP make_pair
#define PB push_back
#define sz(x) ((int)(x).size())
#define clr(ar,val) memset(ar, val, sizeof(ar))
#define istr stringstream
#define FOR(i,n) for(int i=0;i<(n);++i)
#define forIt(mp,it) for(__typeof(mp.begin()) it = mp.begin();it!=mp.end();it++)
const double EPS = 1e-6;
const int INF = 0x3fffffff;
const LL LINF = INF * 1ll * INF;
const double PI = acos(-1.0);

#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define lowbit(u) (u&(-u))
#define MAXN 105
#define MAXE (MAXN*MAXN)>>1

typedef int Type;

class Dijkstra
{
public:
    int head[MAXN],nxt[MAXE],cnt;
    Type d[MAXN];
    struct Edge
    {
        int v;
        Type cost;
        Edge() {}
        Edge(int v,Type cost):v(v),cost(cost) {}
        bool operator<(const Edge& ed) const
        {
            return cost>ed.cost;
        }
    } e[MAXE];
    bool vis[MAXN];

    //初始化，n为点数
    void init(int n)
    {
        cnt = 0;
        for(int i = 0; i<n; i++)
            head[i] = -1;
    }

    inline void addEdge(int u,int v,Type cost)
    {
        e[cnt] = Edge(v,cost);
        int tmp = head[u];
        head[u] = cnt;
        nxt[cnt++] = tmp;
    }

    Type dijkstra(int s,int t,int n)
    {
        for(int i = 0; i<n; i++)
            d[i] = INF,vis[i] = false;
        d[s] = 0;
        priority_queue<Edge> q;
        q.push(Edge(s,0));
        while(!q.empty())
        {
            Edge ed = q.top();
            q.pop();
            vis[ed.v] = true;
            if(ed.v==t) //如果未给出终点t，则完全可以不要跟t有关的语句
                return d[t];
            for(int i = head[ed.v]; ~i; i = nxt[i])
            {
                Edge ee = e[i];
                if(!vis[ee.v]&&d[ee.v]>d[ed.v]+ee.cost)
                {
                    d[ee.v] = d[ed.v]+ee.cost;
                    /*
                     *  最短路树
                    	p[ee.v] = MP(u,i);
                    */
                    q.push(Edge(ee.v,d[ee.v]));
                }
            }
        }
        return d[t];
    }

    void buildGraph(int n)
    {
        for(int i=0; i<n; i++)
        {
            int u,num;
            scanf("%d%d",&u,&num);
            while(num--)
            {
                int v,w;
                scanf("%d%d",&v,&w);
                addEdge(u,v,w);
            }
        }
    }
} dij;

int main()
{
    int n;
    scanf("%d",&n);
    dij.init(n);
    dij.buildGraph(n);
    for(int i=0; i<n; i++)
        printf("%d %d\n",i,dij.dijkstra(0,i,n));
    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];

int 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;
    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;
}