Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Node struct {
	cost int
	done bool
}

type Edge struct {
	to, cost int
}

const INF = 1 << 60

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	nodes := make([]Node, N)
	for i := 0; i < N; i++ {
		nodes[i].cost = INF
	}
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id] = append(E[id], Edge{to, cost})
		}
	}
	nodes[0].cost = 0
	for {
		cur := 0
		minCost := INF
		for i := 0; i < N; i++ {
			n := nodes[i]
			if !n.done && n.cost < minCost {
				cur = i
				minCost = n.cost
			}
		}
		if minCost == INF {
			break
		}
		nodes[cur].done = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+nodes[cur].cost
			if !nodes[to].done && cost < nodes[to].cost {
				nodes[to].cost = cost
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, nodes[i].cost)
	}
	wtr.Flush()
}

C++: // -*- mode:c++; coding:utf-8; c-basic-offset:2; -*-
// ALDS1_12_B: Single Source Shortest Path I

#include <algorithm>
#include <cstdio>

using uint = unsigned int;

class Graph {
  const uint n_;
  uint* const g_;
  const uint INFINIT;
  
public:

  Graph(uint n) : n_(n), g_(new uint[(n_*n_)]), INFINIT(100000*(n_-1)+1) {
    std::fill_n(g_, (n_*n_), INFINIT);
  }

  ~Graph() { delete[] g_; }
  
  uint* operator [](uint i) const { return g_+(n_*i); }

  void dijkstra(uint* dist)
  {
    std::fill_n(dist, n_, INFINIT);
    auto i = 0u; // 0-start
    dist[i] = 0u;
    for (auto n = 0u; n < n_-1; ++n) {
      auto cur_min = INFINIT;
      auto cs = (*this)[i];
      auto c = dist[i];
      for (auto j = 0u; j < n_; ++j) {
        auto nc = c+cs[j];
        if (dist[j] < nc) continue;
        dist[j] = nc;
        if (cur_min > nc) {
          i = j;
          cur_min = nc;
        }
      }
    }
  }
};

int main()
{
  uint n;
  std::scanf("%u", &n);

  Graph g(n);

  uint u, k, v, c;
  for (auto i = 0u; i < n; ++i) {
    std::scanf("%u %u", &u, &k);
    for (auto j = 0u; j < k; ++j) {
      std::scanf("%u %u", &v, &c);
      g[u][v] = c;
    }
  }

  uint dist[n];
  g.dijkstra(dist);
  for (auto i = 0u; i < n; ++i) {
    std::printf("%u %u\n", i, dist[i]);
  }
}

// eof

C++: #include <iostream>
using namespace std;
const int MAXn = 100;
const int INFTY = 1 << 21;

int n, M[MAXn][MAXn], col[MAXn], d[MAXn], p[MAXn];

void dijkstra(int s) {
    for(int i = 0; i < n; i++) {
        col[i] = 0;
        d[i] = INFTY;
    }
    d[s] = 0;
    p[s] = -1;

    while(1) {
        int mincost = INFTY;
        int u;
        for(int i = 0; i < n; i++) {
            if(col[i] != 2 && d[i] < mincost) {
                mincost = d[i];
                u = i;
            }
        }
        if(mincost == INFTY) break;
        col[u] = 2;
        for(int v = 0; v < n; v++) {
            if(col[v] != 2 && M[u][v] != INFTY) {
                if(d[u] + M[u][v] < d[v]) {
                    d[v] = d[u] + M[u][v];
                    p[v] = u;
                    col[v] = 1;
                }
            }
        }
    }

    for(int i = 0; i < n; i++)
        cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << endl;

    return;
}

int main() {
    cin >> n;
    int id, k, v, c;
    for(int i = 0; i < n; i++)
        for(int j = 0; j < n; j++) M[i][j] = INFTY;
    for(int i = 0; i < n; i++) {
        cin >> id >> k;
        for(int j = 0; j < k; j++) {
            cin >> v >> c;
            M[id][v] = c;
        }
    }
    dijkstra(0);
    return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <cstring>
#define MAX 105
#define INF 1000000
using namespace std;

int n;
int color[MAX];//0 表示未进入 -1 表示在之中 1 表示已出去 
int p[MAX];
int M[MAX][MAX];
int d[MAX];

void dijkstra() {
	int i,j,u;
	d[0]=0;
	p[0]=-1;
	while(1) {
		int min=INF;
		u=-1;
		for(i=0;i<n;i++) {
			if(d[i]<min && color[i]!=1) {
				min=d[i];
				u=i;
			}
		}
		if(u==-1) break;
		color[u]=1;
		for(j=0;j<n;j++) {
			if(color[j]!=1 && d[j]>min+M[u][j]) {
				color[j]=-1;
				d[j]=min+M[u][j];
				p[j]=u;
			}
		}
	}
}

int main() {
	memset(d,INF,sizeof(d));
	memset(color,0,sizeof(color));
	memset(p,-1,sizeof(p));
	memset(M,INF,sizeof(M));
	int i,j,u,k,v,c;
	cin>>n;
	for(i=0;i<n;i++) {
		cin>>u>>k;
		for(j=0;j<k;j++) {
			cin>>v>>c;
			M[u][v]=c;
		}
	}
	dijkstra();
	for(i=0;i<n;i++) {
		cout<<i<<' '<<d[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;
}