Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type DirectedGraphNodeID int

type DirectedGraphNode struct {
	key         DirectedGraphNodeID
	adjacents   []*DirectedGraphNode
	costs       []int
	distance    int
	predecessor *DirectedGraphNode
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for i := 0; i < nNodes; i++ {
		node := DirectedGraphNode{}
		node.key = DirectedGraphNodeID(i)
		node.distance = infty
		graph.nodes[i] = &node
	}
	return &graph
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(i, j DirectedGraphNodeID, cost int) {
	g.nodes[i].adjacents = append(g.nodes[i].adjacents, g.nodes[j])
	g.nodes[i].costs = append(g.nodes[i].costs, cost)
}

func (g *DirectedGraph) print() {
	for i := 0; i < len(g.nodes); i++ {
		node := g.nodes[i]
		key := node.key
		strings := []string{strconv.Itoa(int(key)), strconv.Itoa(node.distance)}
		for j := 0; j < len(node.adjacents); j++ {
			nodeJ := fmt.Sprintf("(%v, %v)", node.adjacents[j].key, node.costs[j])
			strings = append(strings, nodeJ)
		}
		fmt.Printf("%v\n", strings)
	}
}

func (g *DirectedGraph) relaxEdge(l, r *DirectedGraphNode, w int) {
	if r.distance > l.distance+w {
		// fmt.Printf("%v -> %v, %v\n", l.key, r.key, l.distance+w)
		r.distance = l.distance + w
		r.predecessor = l
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	graph := newDirectedGraph(nNodes)

	for i := 0; i < nNodes; i++ {
		iNode := DirectedGraphNodeID(nextInt())
		nAdjacent := nextInt()
		for j := 0; j < nAdjacent; j++ {
			jNode := DirectedGraphNodeID(nextInt())
			cost := nextInt()
			graph.setAdjacency(iNode, jNode, cost)
		}
	}

	graph.nodes[0].distance = 0
	for iNode := 0; iNode < nNodes; iNode++ {
		for iLeft := 0; iLeft < len(graph.nodes); iLeft++ {
			nodeLeft := graph.nodes[iLeft]
			for iRight := 0; iRight < len(nodeLeft.adjacents); iRight++ {
				nodeRight := nodeLeft.adjacents[iRight]
				cost := nodeLeft.costs[iRight]
				graph.relaxEdge(nodeLeft, nodeRight, cost)
			}
		}
	}

	// graph.print()

	for iNode := 0; iNode < len(graph.nodes); iNode++ {
		node := graph.nodes[iNode]
		fmt.Println(node.key, node.distance)
	}
}

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;
}