Go: package main

import (
	"fmt"
	"bufio"
	"os"
	"strconv"
	"container/heap"
)

type Node struct {
	Id int
	Dis int
}

type PriorityQueue []*Node

func (pq PriorityQueue) Len() int { return len(pq) }

func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].Dis < pq[j].Dis
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
}

func (pq *PriorityQueue) Push(x interface{}) {
	*pq = append(*pq, x.(*Node))
}

func (pq *PriorityQueue) Pop() interface{} {
	n := len(*pq)
	pop := (*pq)[n-1]
	*pq = (*pq)[0:n-1]
	return pop
}

func main() {
	var n int
	fmt.Scan(&n)

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

	g := make([][]int, n)
	c := make([][]int, n)
	pq := make(PriorityQueue, 0, n)
	d := make([]int, n)
	for i := 0; i < n; i++ {
		sc.Scan()
		u, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		k, _ := strconv.Atoi(sc.Text())
		g[u] = make([]int, k)
		c[u] = make([]int, k)
		for j := 0; j < k; j++ {
			sc.Scan()
			g[u][j], _ = strconv.Atoi(sc.Text())
			sc.Scan()
			c[u][j], _ = strconv.Atoi(sc.Text())
		}

		if u == 0 {
			d[u] = 0
		} else {
			d[u] = 1 << 30
		}
		pq.Push(&Node{u, d[u]})
	}
	heap.Init(&pq)

	for pq.Len() > 0 {
		node := heap.Pop(&pq).(*Node)
		for i := 0; i < len(g[node.Id]); i++ {
			nextId := g[node.Id][i]
			nextDis := node.Dis + c[node.Id][i]
			if nextDis < d[nextId] {
				d[nextId] = nextDis
				heap.Push(&pq, &Node{nextId, nextDis})
			}
		}
	}

	wr := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		wr.WriteString(strconv.Itoa(i))
		wr.WriteString(" ")
		wr.WriteString(strconv.Itoa(d[i]))
		wr.WriteString("\n")
	}
	wr.Flush()
}

C++: #include <bits/stdc++.h>
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#define INF INT_MAX/3
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define llong long long
#define pb(a) push_back(a)
using namespace std;
typedef pair<int, int> P;
typedef pair<llong, llong> LP;
typedef pair<int, P> PP;
typedef pair<llong, LP> LPP;

int dy[]={0, 0, 1, -1, 0};
int dx[]={1, -1, 0, 0, 0};

#define MAX_N 10000
int G[MAX_N][MAX_N];
int MIN_COSTS[MAX_N];

int main() {
  int n;
  cin >> n;
  REP(i, n) {
    REP(j, n) {
      G[i][j] = INT_MAX;
    }
    MIN_COSTS[i] = INT_MAX;
  }
  int u, k;
  int v, c;
  REP(i, n) {
    cin >> u >> k;
    REP(j, k) {
      cin >> v >> c;
      G[u][v] = c;
    }
  }

  priority_queue<P> q;
  int position;
  int new_cost;
  q.push(P(0, 0));
  while (q.size() != 0){
    position = q.top().first;
    MIN_COSTS[position] = q.top().second;
    q.pop();
    REP(i, n) {
      if (G[position][i] != INT_MAX) {
        new_cost = MIN_COSTS[position] + G[position][i];
        if (new_cost < MIN_COSTS[i]) {
          MIN_COSTS[i] = new_cost;
          q.push(P(i, new_cost));
        }
      }
    }
  }

  REP(i, n) {
    cout << i << ' ' << MIN_COSTS[i] << endl;
  }

  return 0;
}

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

#define N 10001
#define INF 1500001 
int n;

vector<pair<int, int>> A[N];
int color[N];
int d[N];

void dijkstra(int root) {
    priority_queue<pair<int, int>> Q;
    Q.push(make_pair(0, root));

    int treeSize = 1;
    while(!Q.empty()) {
        pair<int, int> addedInfo = Q.top();
        Q.pop();
        int added = addedInfo.second;

        if (color[added] != 1) {
            d[added] = -1 * addedInfo.first;
            color[added] = 1;

            for (vector<pair<int, int>>::iterator it = A[added].begin(); it != A[added].end(); it++) {
                pair<int, int> node_pair = *it;
                if (color[node_pair.first] == 0 && (d[added] + node_pair.second) < d[node_pair.first]) {
                    d[node_pair.first] = d[added] + node_pair.second;
                    Q.push(make_pair(-1 * d[node_pair.first], node_pair.first));
                }
            }
        }
    }
}

int main() {
    cin >> n;

    int w;
    int node;
    int k;
    int ad;
    for (int i = 0; i < n; i++) {
        color[i] = 0;
        d[i] = INF;

        cin >> node >> k;
        for (int j = 0; j < k; j++) {
            cin >> ad >> w;
            A[node].push_back(make_pair(ad, w));
        }
    }

    dijkstra(0);

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

    return 0;
}

C++: #include<iostream>
#include<climits>
#include<vector>
#include<list>
#include<functional>
#include<algorithm>
#include<string>
#include<cmath>
#include<complex>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<deque>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) for(int i=0;i<(n);i++)
#define INF (int)1e9
#define INFL (ll)1e11
using namespace std;
typedef long long ll;
typedef pair<int, int> P;

void dijkstra(vector<vector<int>> v, vector<vector<int>> c, vector<int> &d) {
	d[0] = 0;
	priority_queue<P, vector<P>, greater<P>> pq;
	pq.push(P(0, 0));
	while (!pq.empty()) {
		int s = pq.top().second;
		int dis = pq.top().first;
		pq.pop();
		if (dis > d[s]) continue;
		REP(j, v[s].size()) {
			int u = v[s][j];
			int w = c[s][j];
			if (d[u] > d[s] + w) {
				d[u] = d[s] + w;
				pq.push(P(d[u], u));
			}
		}
	}
}

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int n;
	cin >> n;
	vector<vector<int>> v(n), c(n);
	REP(i, n) {
		int u, k;
		cin >> u >> k;
		v[u] = vector<int>(k);
		c[u] = vector<int>(k);
		REP(j, k) cin >> v[u][j] >> c[u][j];
	}
	vector<int> d(n, INF);
	dijkstra(v, c, d);
	REP(i, n) {
		cout << i << " " << d[i] << "\n";
	}
	
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

#define N_MAX 100

typedef pair<int, int> node;
typedef vector<node> Adj_list;
typedef vector<Adj_list> Adj_lists;

class less_cost{
public:
  bool operator()(const pair<int, int> lhs, const pair<int, int> rhs) const{
    return lhs.second < rhs.second;
  }
};

int main(){

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

  Adj_lists adj_lists(n);

  // read weigts
  for(int i=0; i<n; i++){
    int u, k;
    scanf("%d %d", &u, &k);
    for(int j=0; j<k; j++){
      int v,c;
      scanf("%d %d", &v, &c);
      adj_lists.at(u).push_back(node(v, c));
    }
  }

  // initialize cost
  priority_queue<node, vector<node>, less_cost> pq;
  pq.push(node(0, 0));
  vector<int> d(n, INT_MAX);
  d.at(0) = 0;

  //dijkstra's algorithm
  while(!pq.empty()){
    // extract node u in V-S that has minimum cost
    node u = pq.top();
    pq.pop();

    // if u's cost is larger than d[u],
    // than ignore this one
    if(u.second < d.at(u.first)) continue;

    // update node in V-S and adjacent to u
    for(const node& v : adj_lists.at(u.first)){
      if(d[u.first] + v.second < d[v.first]){
        d[v.first] = d[u.first] + v.second;
        pq.push(node(v.first, d[v.first]));
      }
    }
  }

  // output
  for(int i=0; i<n; i++){
    printf("%d %d\n", i, d[i]);
  }

  return 0;
}