Go: package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

const (
	INFTY = 1 << 21
	NIL   = -1
)

const (
	WHITE = iota
	GRAY
	BLACK
)

type Graph [][]int

func (g *Graph) dikstra(n int) string {
	var (
		u, minv = 0, 0
	)

	d := make([]int, n)
	color := make([]int, n)

	for i := 0; i < n; i++ {
		d[i] = INFTY
		color[i] = WHITE
	}
	d[0] = 0
	color[0] = GRAY

	for {
		minv = INFTY
		u = -1
		for 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 v := 0; v < n; v++ {
			if color[v] != BLACK && (*g)[u][v] != INFTY {
				if d[v] > d[u]+(*g)[u][v] {
					d[v] = d[u] + (*g)[u][v]
					color[v] = GRAY
				}
			}
		}
	}

	var out bytes.Buffer
	for i := 0; i < n; i++ {
		out.WriteString(fmt.Sprintf("%d ", i))
		if d[i] == INFTY {
			out.WriteString(fmt.Sprintf("%d\n", -1))
			continue
		}
		out.WriteString(fmt.Sprintf("%d\n", d[i]))
	}

	return strings.TrimRight(out.String(), "\n")
}

func answer(reader io.Reader) string {
	sc := bufio.NewScanner(reader)
	sc.Split(bufio.ScanWords)

	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())

	g := make(Graph, n)
	for i := 0; i < n; i++ {
		g[i] = make([]int, n)
		for j := 0; j < n; j++ {
			g[i][j] = INFTY
		}
	}

	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())

		for j := 0; j < k; j++ {
			sc.Scan()
			v, _ := strconv.Atoi(sc.Text())
			sc.Scan()
			c, _ := strconv.Atoi(sc.Text())

			g[u][v] = c
		}
	}

	return g.dikstra(n)
}

func main() {
	fmt.Println(answer(os.Stdin))
}

C++: #define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<cstdio>
#include<string>
#include<algorithm>
#include<cmath>
using namespace std;

#define REP(i,n) for(int i=0;(i)<(n);(i)++)

static const int INFTY = (1 << 29);
static const int WHITE = 0; //?????¢?´¢
static const int GRAY = 1; //??¢?´¢??????
static const int BLACK = 2; //?¨??????????

int n, M[101][101];

void dijkstra(void) {
	int dist[101]; //?§????????????????i????§????????????????????????????
	int color[101]; //?¨??????¶???(???or??°or???)

	//?????????????????§?????????????¨??????¶???????????§?????????
	REP(i, n) {
		dist[i] = INFTY;
		color[i] = WHITE;
	}

	dist[0] = 0; //?§????0??????0?????§???????????????0
	color[0] = GRAY; //0?????¢?´¢??????	

	//?????¢?´¢???????????????????????????????°??????????????§????????????????????????´??°????????????
	int minCost;
	while (true) {
		minCost = INFTY; //????°??????????????????????
		int minNode = -1; //????°?????????????????????????????????????
		REP(i, n) {
			if (minCost > dist[i] && color[i] != BLACK) {
				minNode = i;
				minCost = dist[i];
			}
		}
		if (minNode == -1) break; //-1???????????¨???????????¨????????????????????????????????£?????¨???????????¨

		color[minNode] = BLACK; //????°??????????????????????????§??????????????¨???????????????????

		//??¢?´¢????????????????????????????????´??°??????
		REP(v, n) {
			if (color[v] != BLACK && M[minNode][v] != INFTY) {
				if (dist[v] > dist[minNode] + M[minNode][v]) {
					dist[v] = dist[minNode] + M[minNode][v];
					color[v] = GRAY;
				}
			}
		}
	}
	
	REP(i, n) {
		cout << i << " " << (dist[i] == INFTY ? -1 : dist[i]) << endl;
	}

}

int main() {
	cin >> n;

	//??£??\???????????????????????§?????????
	REP(i, n) {
		REP(j, n) {
			M[i][j] = INFTY;
		}
	}

	//??£??\??????????????????
	int u, k, v, c;
	REP(i, n) {
		cin >> u >> k;
		REP(j, k) {
			cin >> v >> c;
			M[u][v] = c;
		}
	}

	dijkstra();

	
	return 0;
}

C++: #include<cstdio>
#include<iostream>
#define INF 200001 
using namespace std;
int main(){
 int u,k,C,V,A[1000][1000],D[1000][1000],n;
  scanf("%d",&n);
   for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = INF;
  for(int i=0;i<n;i++){
      scanf("%d %d",&u,&k);    
      for(int j=0;j<k;j++){
    scanf("%d %d",&V,&C);
    D[u][V] = C;
      }    
  }
  for(int i=0;i<n;i++)D[i][i] = 0;
  for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j]= min(D[i][j],D[i][k] + D[k][j]);
  for(int i=0;i<n;i++)printf("%d %d\n",i,D[0][i]);
  return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
using namespace std;


int main() {
    int N; cin >> N;
    int u, k, v, c; 
    const int inf = 100000000;
    

    vector<pair<int, int> > G[N];
    for (int i = 0; i < N; ++i) {
        cin >> u >> k;
        for (int j = 0; j < k; ++j) {
            cin >> v >> c;
            G[u].push_back(make_pair(c, v));
        }
    }

    int dist[N]; 
    priority_queue<pair<int, int> > que;

    for (int i = 0; i < N; ++i) {
        if (i) dist[i] = inf;
        else dist[i] = 0;
    }
    que.push(make_pair(0, 0));

    while (!que.empty()) {
        pair<int, int> f = que.top(); que.pop();
        int cur_cost = f.first*(-1);
        int cur_vtx = f.second;

        if (dist[cur_vtx] < cur_cost) continue;

        for (int i = 0; i < G[cur_vtx].size(); ++i) {
            int next_cost = G[cur_vtx][i].first;
            int next_vtx = G[cur_vtx][i].second;

            if (dist[next_vtx] > cur_cost + next_cost) {
                dist[next_vtx] = cur_cost + next_cost;
                que.push(make_pair(dist[next_vtx]*(-1), next_vtx));
            }
        }   
    }

    for (int v = 0; v < N; ++v) cout << v<< " " << dist[v] << endl;

    return 0;
}

C++: #include <iostream>

using namespace std;

static const int MAX = 100;
static const int INF = 1 << 30;
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] = INF;
        color[i] = WHITE;
    }

    d[0] = 0;

    while (true){
        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;
}

C++: #include <iostream>
#include <queue>
#include <utility>
#include <vector>
#include <functional>
using namespace std;
int cost[100][100];
const int INF = 10000000;
int dijkstra(int n,int s,int g){
	typedef pair<int,int> P;
	priority_queue<P,vector<P>,greater<P> > pq;
	P p,tp;
	for(int i = 0;i < n;++i){
		p.first = cost[s][i];
		p.second = i;
		if(i == s) p.first = 0;
		pq.push(p);
	}
	while(!pq.empty()){
		p = pq.top();
		pq.pop();
		if(p.second == g) break;
		for(int i = 0;i < n;++i){
			if(cost[p.second][i] != INF && p.first != INF){
				tp.first = p.first + cost[p.second][i];
				tp.second = i;
				pq.push(tp);
			}
		}
	}
	return p.first;
}
int main(){
	int n,m,a,b,c;
	cin >> n;
	for(int i = 0;i < 100;++i){
		for(int j = 0;j < 100;++j){
			cost[i][j] = INF;
		}
	}
	for(int i = 0;i < n;++i){
		cin >> a >> m;
		for(int j = 0;j < m;++j){
			cin >> b >> c;
			cost[a][b] = c;
		}
	}
	for(int i = 0;i < n;++i){
		cout << i << " " << dijkstra(n,0,i) << endl;
	}
	return 0;
}