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++: #include<iostream>
#include<cstdio>
#include<climits>
#include<cstring>
#define INF INT_MAX
using namespace std;
typedef unsigned long long ull;
int n;
int A[1000][1000];
bool used[1000];
ull D[1000][1000];
 
void Init(int f){
  for(int i=0;i<f;i++){
    for(int j=0;j<f;j++)D[i][j] = INF;
  }
 
}
 
int main(){
  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 <bits/stdc++.h>
using namespace std;


typedef pair<int, int> P;
#define int long long

const int INF = LONG_LONG_MAX;
struct edge {int to, cost;};

/*
[input]
const vector<vector<edge>> &graph : ??\?????°??????
int s : ?§????
int g : ??????
n*/
int dijkstra(const vector<vector<edge>> &graph, int s, int g ) {
  // ????????????????±?????????????????????????
  vector<int> d(graph.size(), INF);
  // ????§?????????????????????????0????????????
  d[s] = 0;
  // ??????????????????now
  set<P> now;
  // ????§?????????????now????????\
  now.insert(P(0, s));
  
  // now????????????????????§
  while(!now.empty()) {
    // ?????¨?????????????????????pos???????´?
    int pos = now.begin()->second;
    // ?????¨??????????????????????????????????±???????????????????????????????
    if (pos == g) {
      for(int i = 0; i <= g; i++) {
        cout << i << " " << d[i] << endl;
      }
      return INF;
    }
    // now????????¢?´¢?????????????¶????
    now.erase(now.begin());
    // ?????¨??????????????¨???????????¢?´¢
    for(auto ed: graph[pos]) {
      // ??\?¶??????????????????????????????????????????¨??????????????§????????????
      // ??¨??\?¶?????????§?????¨????????????????????????????????§???????????°
      if(d[ed.to] > d[pos] + ed.cost) {
        // now????????\?¶?????????????????±????????????????????????????
        now.erase(P(d[ed.to], ed.to));
        d[ed.to] = d[pos] + ed.cost;
        now.insert(P(d[ed.to], ed.to));
      }
    }
  }
  return INF;
}
  
signed main() {
  int num;
  cin >> num;
  vector<vector<edge>> graph(num, vector<edge>());
  int f, n, k, v, c;
  for(int i = 0; i < num; i++) {
    cin >> f >> k;
	if(k == 0) continue;
    for(int j = 0; j < k; j++) {
      cin >> v >> c;
      graph[f].push_back(edge{v, c});
      graph[v].push_back(edge{f, c});
    }
  }
  dijkstra(graph, 0, num - 1);
  return 0;
}

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

struct Node {
  int v, cost;
  bool operator>(const Node &n) const {
    return cost > n.cost;
  }
};

int main() {
  int n;
  cin >> n;

  vector<vector<int>> g(n, vector<int>(n, -1));
  for (int i = 0; i < n; i++) {
    int u, k;
    cin >> u >> k;
    for (int j = 0; j < k; j++) {
      int v, c;
      cin >> v >> c;
      g[u][v] = c;
    }
  }

  vector<int> dists(n, -1);
  priority_queue<Node, vector<Node>, greater<Node>> q;
  q.push({0, 0});
  while (!q.empty()) {
    Node node = q.top();
    q.pop();

    if (dists[node.v] != -1) {
      continue;
    }
    dists[node.v] = node.cost;

    for (int i = 0; i < n; i++) {
      if (g[node.v][i] != -1) {
	q.push({i, node.cost + g[node.v][i]});
      }
    }
  }

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

  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <set>
#include <cmath>
#include <deque>
#include <iterator>
#include <map>
#include <queue>
#include <string>
#include <tuple>
#include <utility>
using namespace std;

using ll=long long;
template<class T> using V = vector<T>;
template<class T, class U> using P = pair<T, U>;
using vll = V<ll>;
using vvll = V<vll>;
#define rep(i, k, n) for (ll i=k; i<(ll)n; ++i)
#define REP(i, n) rep(i, 0, n)
template<class T> inline bool chmax(T& a, T b) {if (a<b) {a=b; return true;} return false;}
template<class T> inline bool chmin(T& a, T b) {if (a>b) {a=b; return true;} return false;}

const ll MOD = 1000000007;
const ll HIGHINF = (ll)1e18;

int main() {
  ll n; cin >> n;
  vvll edges(n, vll(n, -1));
  REP(i, n) {
    ll u, k; cin >> u >> k;
    REP(j, k) {
      ll v, c; cin >> v >> c;
      edges.at(u).at(v) = c;
    }
  }
  vll d(n, HIGHINF);
  V<bool> visited(n, false);
  d.at(0) = 0;
  REP(i, n) {
    ll now = -1;
    ll mind = HIGHINF;
    REP(j, n) {
      if (!visited.at(j) && d.at(j) < mind) {
        now = j;
        mind = d.at(j);
      }
    }
    REP(j, n) {
      if (edges.at(now).at(j) != -1 && d.at(j) > d.at(now) + edges.at(now).at(j)) {
        d.at(j) = d.at(now) + edges.at(now).at(j);
      }
    }
    visited.at(now) = true;
  }
  REP(i, n) cout << i << ' ' << d.at(i) << endl;
  return 0;
}