Go: package main

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

const BIG_COST = 200000

const (
	ST_NOT_YET = iota
	ST_JOINED
)

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	nNodes := scanInt(sc)

	costs := make([][]int, nNodes)
	graph := make([][]int, nNodes)

	states := make([]int, nNodes)
	costSums := make([]int, nNodes)

	for i := 0; i < nNodes; i++ {
		costs[i] = make([]int, nNodes)
		costSums[i] = BIG_COST
	}

	for i := 0; i < nNodes; i++ {
		u := scanInt(sc)
		k := scanInt(sc)
		graph[u] = make([]int, k)
		for d := 0; d < k; d++ {
			v := scanInt(sc)
			graph[u][d] = v
			costs[u][v] = scanInt(sc)
		}
	}

	costSums[0] = 0
	for {
		minCost := BIG_COST
		var u int

		for i, cost := range costSums {
			if states[i] != ST_JOINED && cost < minCost {
				minCost = cost
				u = i
			}
		}

		if minCost == BIG_COST {
			break
		}

		states[u] = ST_JOINED

		for _, v := range graph[u] {
			cost := minCost + costs[u][v]
			if cost < costSums[v] {
				costSums[v] = cost
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i, cost := range costSums {
		fmt.Fprintf(w, "%d %d\n", i, cost)
	}
	w.Flush()
}

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

C++: //さっさと済ませられるところはさっさと済ましてしまう．ただし注意深く
#include <cstdio>
#include <iostream>
#define MAX_VERTEXES 100
#define NIL -1
#define INFTY 20000000// >100*100000

using namespace std;

//think easy make easy

int n;//num of vertexes(頂点)
int matrix_graph[MAX_VERTEXES+1][MAX_VERTEXES+1];//0オリジン
bool vertex_set[MAX_VERTEXES+1];///0オリジン
int current_mincost[MAX_VERTEXES+1];//現時点での各頂点への最小コスト
bool candidate[MAX_VERTEXES+1];//次にvertex_setに加える頂点の候補

void findNextVertex(){
	int min_tmp=INFTY;
	int next_tmp = NIL;
	for(int i=0;i<n;i++){
		candidate[i] = false;
	}
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			if(vertex_set[i] == true && vertex_set[j] == false){
				if(matrix_graph[i][j]+current_mincost[i] < current_mincost[j]
				   && matrix_graph[i][j] != NIL){
					   current_mincost[j]  = matrix_graph[i][j]+current_mincost[i];
					   candidate[j] = true;
				}
			}
		}
	}
	for(int i=0;i<n;i++){
		if(candidate[i] == true && current_mincost[i] < min_tmp){
			min_tmp = current_mincost[i];
			next_tmp = i;
		}
	}
	vertex_set[next_tmp] = true;
}

int main(){
	scanf("%d",&n);

	int v_num;
	int k;//v_numの出次数

	for(int i=0;i<n;i++){
		for(int j=0;j<=n;j++){
			matrix_graph[i][j] = NIL;
		}
	}

	for(int i=0;i<n;i++){
		scanf("%d",&v_num);
		scanf("%d",&k);

		for(int j=0;j<k;j++){
			int v_num2;
			int cst;
			scanf("%d",&v_num2);
			scanf("%d",&cst);
			matrix_graph[v_num][v_num2] = cst;
		}
	}

	for(int i=0;i<n;i++){
		vertex_set[i] = false;
		current_mincost[i] = INFTY;
	}
	/*確認用
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			if(j<n-1) printf("%d ",matrix_graph[i][j]);
			else printf("%d\n",matrix_graph[i][j]);
		}
	}
	*/

	vertex_set[0] = true;
	current_mincost[0] = 0;
	for(int i=1;i<n;i++){
		findNextVertex();
	}
	for(int i=0;i<n;i++){
		cout <<i <<" " <<current_mincost[i] <<endl;
	}


	return 0;
}

C++: #include <iostream>
#include <stdio.h>
#include <vector>

using namespace std;

struct Wside{
	int vertex;
	int weight;
	Wside(int a, int b){
		vertex=a; weight=b;
	}
};

vector<Wside>* info;
vector<int> scanned;
int* result;
int n, mark;

bool isScanned(int v){
	for(int i=0,sz=scanned.size(); i<sz; ++i){
		if(v==scanned[i]) return 1;
	}
	return 0;
}

int scan(){
	int nextvtx = -1;
	for(int j=0, scn=scanned[scanned.size()-1], sz=info[scn].size(); j<sz; ++j){
		int vtx = info[scn][j].vertex;
		if(isScanned(vtx)) continue;
		int wgh = info[scn][j].weight;
		result[vtx] = result[vtx] > result[scn] + wgh ? (result[scn] + wgh) : result[vtx];
	}

	for(int i=0; i<n; ++i){
		if(!isScanned(i)){
			if(nextvtx == -1){
				nextvtx = i;
				continue;
			}
			nextvtx = result[nextvtx] < result[i]? nextvtx : i ;
		}
	}
	scanned.push_back(nextvtx);
	return 0;
}

int main()
{
	scanf("%d",&n);
	scanned.reserve(n);
	info = new vector<Wside> [n];
	result = new int [n];
	for(int i=0; i<n; ++i){
		result[i] = 0xfffffff;
	}

	int org,k,v,c;
	for(int i=0; i<n; ++i){
		scanf("%d %d",&org,&k);
		info[org].reserve(k);
		for(int j=0; j<k; ++j){
			scanf("%d %d",&v,&c);
			info[org].push_back(Wside(v,c));
		}
	}

	scanned.push_back(0);
	result[0] = 0;
	while(scanned.size()!=n){
		scan();
	}

	for(int i=0; i<n; ++i){
		cout << i << " " << result[i] << endl;
	}

	delete[] info;
	delete[] result;

	return 0;
}

C++:  #include<iostream>
#include<queue>
#define INF 100000000
using namespace std;
int main(){
  int n;cin>>n;
  int u,k,v,c;
  int mp[101][101],d[101];
  for(int i=0;i<=100;i++){
    d[i]=INF;
    for(int j=0;j<=100;j++)mp[i][j]=INF;
  }
    while(u!=n-1){
    cin>>u>>k;
    for(int i=0;i<k;i++){
      cin>>v>>c;
      if(mp[u][v]>c)mp[u][v]=c;
    }
  }
    d[0]=0;
    queue<int>p;
    p.push(0);
    int mn,s=0,cnt=n-1;
    while(cnt&&!p.empty()){
      s=p.back();
      mn=INF;
      for(int i=0;i<n;i++){
	if(d[i]>=d[s]+mp[s][i]){
	  d[i]=d[s]+mp[s][i];
	  if(mn>d[i])mn=d[i],k=i;
	}
      }
      if(mn!=INF)cnt--,p.push(k);
      else p.pop();
    }
    for(int i=0;i<n;i++)cout<<i<<" "<<d[i]<<endl;
    
  return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<algorithm>

#define MAX 100
static const int INFTY =(1<<21);

int n,M[MAX][MAX];
int unvisited=0,decide=1,comp_decide=2;

void dijkstra(){
	int d[MAX];
	int state[MAX];
	for(int i=0;i<n;i++){
		d[i]=INFTY;
		state[i]=unvisited;
	}
	d[0]=0;
	state[0]=0;
	while(1){
		int mincost=INFTY,u=-1;
		for(int i=0;i<n;i++){
			if(d[i]<mincost&&state[i]!=comp_decide){
				u=i;
				mincost=d[i];
			}
		}
		if(u==-1) break;
		state[u]=comp_decide;
		for(int v=0;v<n;v++){
			if(state[v]!=comp_decide&&M[u][v]!=INFTY){
				if(d[v]>d[u]+M[u][v]){
					d[v]=d[u]+M[u][v];
					state[v]=decide;
				}
			}
		}
	}
	for(int i=0;i<n;i++){
			printf("%d %d\n",i,(d[i]==INFTY ? -1:d[i]));
	}
}

int main(){
	scanf("%d",&n);
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			M[i][j]=INFTY;
		}
	}
	int u,k,v,c;
	for(int i=0;i<n;i++){
		scanf("%d %d",&u,&k);
		for(int j=0;j<k;j++){
			scanf("%d %d",&v,&c);
			M[u][v]=c;
		}
	}
	dijkstra();
}

C++: #include<iostream>
using namespace std;
#define MAX 100
#define INF (1<<21)
#define WHITE 0
#define GRAY 1
#define 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] = INF;
    color[i] = WHITE;
  }

  d[0] = 0;
  color[0] = GRAY;
  while(1){
    minv = INF;
    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] != INF){
	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] == INF ? -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]  = INF;
    }
  }
  
  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;
}