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++: #include <bits/stdc++.h>
using namespace std;
#define MAX 105
#define INFTY INT_MAX

int n, G[MAX][MAX];

void dijkstra() {
    int d[MAX], color[MAX];
    for (int i = 0; i < n; i++) {
        d[i] = INFTY;
        color[i] = 0;
    }
    d[0] = 0;
    while (1) {
        int u = -1;
        int minv = INFTY;
        for (int i = 0; i < n; i++) {
            if (color[i] != 1 && d[i] < minv) {
                minv = d[i];
                u = i;
            }
        }
        if (minv == INFTY)
            break;
        color[u] = 1;
        for (int v = 0; v < n; v++) {
            if (color[v] != 1 && G[u][v] != INFTY) {
                if (d[u] + G[u][v] < d[v])
                    d[v] = d[u] + G[u][v];
            }
        }
    }
    for (int i = 0; i < n; i++) {
        cout << i << " " << d[i] << endl;
    }
}

int main(void) {
    cin >> n;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            G[i][j] = INFTY;
        }
    }
    int k, v, c;
    for (int i = 0; i < n; i++) {
        cin >> k >> k;
        while (k--) {
            cin >> v >> c;
            G[i][v] = c;
        }
    }
    dijkstra();
    return 0;
}

C++: #include<stdio.h>
#include<queue>
#include<algorithm>
using namespace std;
const int white=0;
const int black=1;
const int nil=(1<<21);
int n;
int d[200],color[200];
vector<pair<int,int> >tu[200];
priority_queue<pair<int,int> >PQ;
void prim()
{
    for (int i=0;i<n;i++)
    {
        d[i]=nil;
    }
    d[0]=0;
    PQ.push(make_pair(0,0));
    while(!PQ.empty())
    {
        pair<int,int> f=PQ.top();
        PQ.pop();
        int u=f.second;
        color[u]=black;
        if(d[u]<f.first*(-1))
            continue;
        for (int j=0;j<tu[u].size();j++)
        {
            int v=tu[u][j].first;
            if(color[v]==black) continue;
            if(d[v]>d[u]+tu[u][j].second)
            {
                d[v]=d[u]+tu[u][j].second;
                PQ.push(make_pair(d[v]*(-1),j));
            }
        }
    }
    for (int i=0;i<n;i++)
        printf("%d %d\n",i,((d[i]==-1)?-1:d[i]));
}
int main()
{
    int u,k,v,c;
    scanf("%d",&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);
            tu[u].push_back(make_pair(v,c));
        }
    }
    prim();
        return 0;
}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#define MAX_V 100
#define INF 1e9
using namespace std;
int cost[MAX_V][MAX_V];
int d[MAX_V];
bool used[MAX_V];
int V;
void dijkstra(int s) {
	for (int i = 0; i < V; i++) {
		d[i] = INF;
		used[i] = false;
	}
	d[s] = 0;
	while (true) {
		int v = -1;
		for (int u = 0; u < V; u++) {
			if (!used[u] && ((v == -1) || d[u] < d[v])) {
				v = u;
			}
		}
		//全ての頂点が到達済み
		if (v == -1) {
			break;
		}
		//集合に新たに頂点を追加
		used[v] = true;
		for (int u = 0; u < V; u++) {
			d[u] = min(d[u], d[v] + cost[v][u]);
		}
	}
}

int main() {
	for (int i = 0; i < V+10; i++) {
		for (int j = 0; j < V+10; j++) {
			cost[i][j] = INF;//iからjへの辺の重さ
		}
	}
	cin >> V;
	for (int i = 0; i < V; i++) {
		int u;
		cin >> u;
		int k;
		cin >> k;
		for (int j = 0; j < k; j++) {
			int v;
			cin >> v;
			int c;
			cin >> c;
			cost[u][v] = c;
		}
	}
	dijkstra(0);

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

C++: #include<iostream>
#include<vector>
#include<stack>

#define INF (1 << 21)

int main() {
	int node_num;

	std::cin >> node_num;
	std::vector<std::vector<int> > node(node_num, std::vector<int>(node_num, -1));

	for (size_t i = 0; i < node.size(); i++) {
		int out, node_number;
		std::cin >> node_number >> out;
		for (int j = 0; j < out; j++) {
			int to, distance;
			std::cin >> to >> distance;
			node[node_number][to] = distance;
		}
	}

	std::vector<int> distance(node.size(), INF);
	std::stack<int> s;
	distance[0] = 0;

	s.push(0);
	while(!s.empty()) {
		int node_number = s.top(); s.pop();
		for (size_t j = 0; j < node[node_number].size(); j++) {
			if (node[node_number][j] != -1 && node[node_number][j] + distance[node_number] < distance[j]) {
				distance[j] = node[node_number][j] + distance[node_number];
				s.push(j);
			}
		}
	}

	for (size_t i = 0; i < distance.size(); i++) {
		std::cout << i << " " << distance[i] << std::endl;
	}
}

C++: #include <iostream>
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;
static const int MAX = 2000;

int d[110], p[110];
int color[110];

int main() {
  int n;
  std::cin >> n;
  int G[110][110];

  for(int i=0; i<n; ++i) {
    for(int j=0; j<n; ++j) {
      int v;
      std::cin >> v;
      if(v != -1) {
        G[i][j] = v;
      } else {
        G[i][j] = MAX;
      }
    }
  }

  for(int i=0; i<n; ++i) {
    color[i] = WHITE;
    d[i] = MAX;
  }

  d[0] = 0;
  p[0] = 0;

  while(true) {
    int mini_cost = MAX;
    int u;
    // 最小の重みとなる辺を探している
    for(int i=0; i<n; ++i) {
      if(color[i] != BLACK && d[i] < mini_cost) {
        mini_cost = d[i];
        u = i;
      }
    }

    if(mini_cost == MAX) {
      break;
    }

    color[u] = BLACK;

    for(int v=0; v < n; ++v) {
      if(color[v] != BLACK && G[u][v] != MAX) {
        if(G[u][v] < d[v]) {
          d[v] = G[u][v];
          p[v] = u;
          color[v] = GRAY;
        }
      }
    }
  }

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

  std::cout << d_sum << std::endl;
}