Go: package main

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

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}
func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = i
	pq[j].index = j
}
func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}
func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 // for safety
	*pq = old[0 : n-1]
	return item
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := newQ()
	q.set(0, 0)
	visited := make(map[int]struct{})
	out := make([]int, n)

	for q.len() > 0 {
		u, d := q.pop()
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			dd := d + c
			if d, ok := q.get(uu); !ok || d > dd {
				q.set(uu, dd)
			}
		}

		out[u] = d
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

C++: #ifdef LOCAL_BUILD
#include "pch.h"
#define DLOG(msg) cout << "#" << __LINE__ << ":" << msg << endl;
#define DLOG_V(var) \
  cout << "#" << __LINE__ << ":" << #var << " : " << var << endl;
#else
#include <bits/stdc++.h>
#define DLOG(msg)
#define DLOG_V(var)
#endif
using namespace std;

int main() {
  int n;
  cin >> n;
  vector<vector<pair<int, int>>> edges(n, vector<pair<int, int>>());
  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;
      edges[i].push_back(make_pair(v, c));
    }
  }
  int count = 1;
  constexpr auto not_yet = numeric_limits<int>::max();
  vector<int> costs(n, not_yet);
  costs[0] = 0;
  auto cmp = [](const pair<int, int>& lhs, const pair<int, int>& rhs) {
    return lhs.second > rhs.second;
  };
  priority_queue<pair<int, int>, vector<pair<int, int>>, decltype(cmp)> q(cmp);
  for (auto&& edge : edges[0]) {
    q.push(edge);
  }
  while (true) {
    auto state = q.top();
    q.pop();
    if (costs[state.first] > state.second) {
      assert(costs[state.first] == not_yet);
      for (auto&& edge : edges[state.first]) {
        q.push(make_pair(edge.first, edge.second + state.second));
      }
      costs[state.first] = state.second;
      if (++count == n) {
        break;
      }
    }
  }
  for (int i = 0; i < n; ++i) {
    cout << i << " " << costs[i] << endl;
  }
}

C++: #include <iostream>
const int MAX_N = 100;
const int INF = 999999999;
const int WHITE = 0;
const int GRAY = 1;
const int BLACK = 2;
using namespace std;

int n;
int adj[MAX_N][MAX_N];
int color[MAX_N];
int d[MAX_N];

void dijkstra(int s) {
    for (int i = 0; i < n; i++) {
        color[i] = WHITE;
        d[i] = INF;
    }
    d[s] = 0;
    color[s] = GRAY;

    while (1) {
        int minv = INF;
        int u = -1;
        for (int i = 0; i < n; i++) {
            if (color[i] != BLACK && d[i] < minv) {
                minv = d[i];
                u = i;
            }
        }
        if (u == -1) break;

        color[u] = BLACK;
        for (int v = 0; v < n; v++) {
            if (color[v] != BLACK && adj[u][v] != INF) {
                if (d[v] > d[u] + adj[u][v]) {
                    d[v] = d[u] + adj[u][v];
                    color[v] = GRAY;
                }
            }
        }
    }
}

int main(void) {
    cin >> n;
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++) adj[i][j] = INF;

    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;
            adj[u][v] = c;
        }
    }

    dijkstra(0);

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

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 color[MAX], d[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) {
  	      	  minv = d[i];
  	      	  u = i;
  	      }
      }
      if(u = -1) break;
      color[u] = BLACK;
      for(int v =  0; v < n; i++) {
      	  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;
	int u, k c;
	for(int i = 0; i < n; i++) {
		for(int j = 0; j < n; j++) {
			M[i][i] = INFTY;
		}
	}
	
	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 <queue>
#include <cstdio>
#include <vector>
using namespace std;
int V, s, t, p, q, d[100]; vector<pair<int, int> > G[100];
int main() {
	scanf("%d", &V);
	for(int i = 0; i < V; i++) {
		scanf("%d%d", &s, &t);
		for(int j = 0; j < t; j++) {
			scanf("%d%d", &p, &q);
			G[i].push_back(make_pair(p, q));
		}
	}
	for(int i = 1; i < V; i++) d[i] = 999999999;
	priority_queue<pair<int, int> > que; que.push(make_pair(0, 0));
	while(!que.empty()) {
		int v = que.top().second; que.pop();
		for(int i = 0; i < G[v].size(); i++) {
			int u = G[v][i].first, w = G[v][i].second;
			if(d[u] > d[v] + w) {
				d[u] = d[v] + w;
				que.push(make_pair(-d[u], u));
			}
		}
	}
	for(int i = 0; i < V; i++) printf("%d %d\n", i, d[i]);
	return 0;
}