Go: package main

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

var sc = bufio.NewScanner(os.Stdin)

const T = 10000000

var n int
var A [101][101]int

func nextInt() int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return i
}
func Shortestsearch() {
	var Minimum int
	var d, color [100]int
	var u int

	for i := 0; i < n; i++ {
		d[i] = T
		color[i] = 0
	}

	d[0] = 0
	color[0] = 1

	for {
		Minimum = T
		u = -1
		for i := 0; i < n; i++ {
			if Minimum > d[i] && color[i] != 2 {
				u = i
				Minimum = d[i]
			}
		}
		if u == -1 {
			break
		}
		color[u] = 2
		for j := 0; j < n; j++ {
			if color[j] != 2 && A[u][j] != T {
				if d[j] > d[u]+A[u][j] {
					d[j] = d[u] + A[u][j]
					color[j] = 1
				}
			}
		}
	}
	for i := 0; i < n; i++ {
		fmt.Printf("%d %d\n", i, d[i])
	}
}
func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()

	for i := 0; i < n; i++ {
		for j := 0; j < n; j++ {
			A[i][j] = T
		}
	}
	for i := 0; i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			v := nextInt()
			c := nextInt()
			A[u][v] = c
		}
	}
	Shortestsearch()
}

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;
}

C++: #define _USE_MATH_DEFINES
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <clocale>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

#define IOS ios::sync_with_stdio(false); cin.tie(0);
#define FOR(i, s, n) for(int i = (s), i##_len=(n); i < i##_len; ++i)
#define FORS(i, s, n) for(int i = (s), i##_len=(n); i <= i##_len; ++i)
#define VFOR(i, s, n) for(int i = (s); i < (n); ++i)
#define VFORS(i, s, n) for(int i = (s); i <= (n); ++i)
#define REP(i, n) FOR(i, 0, n)
#define REPS(i, n) FORS(i, 0, n)
#define VREP(i, n) VFOR(i, 0, n)
#define VREPS(i, n) VFORS(i, 0, n)
#define RFOR(i, s, n) for(int i = (s), i##_len=(n); i >= i##_len; --i)
#define RFORS(i, s, n) for(int i = (s), i##_len=(n); i > i##_len; --i)
#define RREP(i, n) RFOR(i, n, 0)
#define RREPS(i, n) RFORS(i, n, 0)
#define ALL(v) (v).begin(), (v).end()
#define SORT(v) sort(ALL(v))
#define RSORT(v) sort(ALL(v), greater<decltype(v[0])>())
#define SZ(x) ((int)(x).size())
#define PB push_back
#define MP make_pair
#define MT make_tuple
#define BIT(n) (1LL<<(n))
#define UNIQUE(v) v.erase(unique(ALL(v)), v.end())

using ll = long long;
using Pi_i = pair<int, int>;
using VB = vector<bool>;
using VC = vector<char>;
using VD = vector<double>;
using VI = vector<int>;
using VLL = vector<ll>;
using VS = vector<string>;
using VSH = vector<short>;

const int MOD = 1000000007;
const int INF = 1000000000;
const int NIL = -1;

template<class T, class S>
bool chmax(T &a, const S &b){
    if(a < b){
        a = b; return true;
    }
    return false;
}
template<class T, class S>
bool chmin(T &a, const S &b){
    if(b < a){
        a = b; return true;
    }
    return false;
}


int V; // 頂点数
vector<vector<int>> d; //d[i][j] iからjまでのコスト 最初辺がなければINF 同じ点では0

void warshallFloyd(){
    REP(k, V) REP(i, V) REP(j, V)
        d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
}

int main(){
    cin >> V;
    d.resize(V, VI(V, INF));
    REP(i, V){
        d[i][i] = 0;
        int u, k; cin >> u >> k;
        REP(j, k){
            int v, c; cin >> v >> c;
            d[u][v] = c;
        }
    }
    warshallFloyd();
    REP(i, V){
        cout << i << " " << d[0][i] << "\n";
    }
    return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<climits>
#include<cstring>
#define INF INT_MAX
using namespace std;
typedef unsigned long long ull;

 
void Init(int f){
  for(int i=0;i<=f+50;i++){
    for(int j=0;j<=f+50;j++)D[i][j] = INF;
  }
}
 
int main(){
int n;
int A[1000][1000];
ull D[1000][1000];
  scanf("%d",&n);
  int u,k,C,V;
  Init(n);
  
  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;
      D[V][u] = 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++){
    cout << i << " " << D[0][i] << endl;
  }
  
  return 0;
}

C++: #include <iostream>
using namespace std;
#define N 100
#define INFTY (1<<21)
#define WHITE 0
#define GRAY 1
#define BLACK 2

int n, M[N][N];

void dijkstra() {
    int minv;
    int d[N], color[N];

    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;
}

C++: #include <bits/stdc++.h>

using namespace std;
typedef pair<int, int> P;

struct edge {
    int t, c;
    edge(int t, int c): t(t), c(c) {}
};

const int INF = 1e9;
int n, u, k, v, c;
vector<edge> G[100];
int d[100];

void dijkstra(int s) {
    fill(d, d + n, INF);
    d[s] = 0;

    priority_queue<P, vector<P>, greater<P> > que;
    que.push(P(0, s));
    while (!que.empty()) {
        P p = que.top(); que.pop();
        int v = p.second;
        if (d[v] < p.first) continue;
        for (int i = 0; i < G[v].size(); i++) {
            edge e = G[v][i];
            if (d[e.t] <= d[v] + e.c) continue;
            d[e.t] = d[v] + e.c;
            que.push(P(d[e.t], e.t));
        }
    }
}

int main(void) {
    cin >> 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(edge(v, c));
        }
    }

    dijkstra(0);

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

    return 0;
}