Go: package main

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

const BIG_COST = 200000

type Path struct {
	node int
	cost int
}

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

	nNodes := scanInt(sc)

	// 各頂点につながる頂点一覧を得るための隣接リスト
	graph := make([][]Path, nNodes)

	for i := 0; i < nNodes; i++ {
		u := scanInt(sc)
		k := scanInt(sc)
		graph[i] = make([]Path, k)
		for d := 0; d < k; d++ {
			graph[u][d] = Path{
				node: scanInt(sc),
				cost: scanInt(sc),
			}
		}
	}

	// 0 から各頂点への最小コストを保存する配列
	minCosts := make([]int, nNodes)

	minCosts[0] = 0
	for i := 1; i < nNodes; i++ {
		minCosts[i] = BIG_COST
	}

	// 各頂点が調査済みかどうかを保持する配列
	checked := make([]bool, nNodes)

	// 最小コストのパスを高速に取得するためのヒープ。
	// コストが小さいものほどルートに来るようにする。
	heap := NewHeap(func(a, b Path) bool {
		return a.cost < b.cost
	})

	heap.insert(Path{node: 0, cost: 0})
	for heap.size > 0 {
		u := heap.extractMax()

		// 隣接行列を使っていた時とは違い、ヒープには
		// 同じノードへのパスが複数含まれうる。そのため既によりコストの低い
		// パスが見つかっている場合は無視する。
		if minCosts[u.node] < u.cost {
			continue
		}

		checked[u.node] = true

		for _, v := range graph[u.node] {
			cost := v.cost + u.cost
			if !checked[v.node] && cost < minCosts[v.node] {
				minCosts[v.node] = cost
				heap.insert(Path{node: v.node, cost: cost})
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i, cost := range minCosts {
		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
}

// --- From ALDS1_9_C: Priority Queue

type Heap struct {
	size   int
	heap   []Path
	isHigh func(a, b Path) bool
}

func NewHeap(isHigh func(a, b Path) bool) Heap {
	heap := make([]Path, 1) // 先頭は不使用
	return Heap{size: 0, heap: heap, isHigh: isHigh}
}

func (h *Heap) insert(v Path) {
	h.size += 1
	if h.size > len(h.heap)-1 {
		h.heap = append(h.heap, v)
	} else {
		h.heap[h.size] = v
	}

	for i := h.size; i > 1; {
		parent := i / 2
		if h.isHigh(h.heap[parent], h.heap[i]) {
			break
		}
		h.heap[i], h.heap[parent] = h.heap[parent], h.heap[i]
		i = parent
	}
}

func (h *Heap) extractMax() Path {
	if h.size <= 0 {
		panic("cannot extract from empty heap")
	}

	max := h.heap[1]
	h.heap[1] = h.heap[h.size]
	h.size -= 1
	h.maxHeapify(1)

	return max
}

func (h *Heap) maxHeapify(idx int) {
	left := idx * 2
	right := left + 1
	largest := idx

	if left <= h.size {
		if h.isHigh(h.heap[left], h.heap[idx]) {
			largest = left
		}
		if right <= h.size && h.isHigh(h.heap[right], h.heap[largest]) {
			largest = right
		}
	}

	if largest != idx {
		h.heap[idx], h.heap[largest] = h.heap[largest], h.heap[idx]
		h.maxHeapify(largest)
	}
}

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

using namespace std;

#define FOR(i,s,e) for((i)=(s);(i)<(int)(e);(i)++)
#define REP(i,e) FOR(i,0,e)

#define all(o) (o).begin(), (o).end()
#define psb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))

typedef long long ll;
typedef pair<int, int> PII;

const double EPS = 1e-10;

typedef struct edge_def {
  int from;
  int to;
  int cost;

  edge_def(int _from, int _to, int _cost) {
    from = _from;
    to   = _to;
    cost = _cost;
  }
} edge;

const int INF = INT_MAX;
const int V = 10000;
int n, t;
vector<edge> es[V];
int d[V];

void dijkstra(int s) {
  int i;
  priority_queue<PII, vector<PII>, greater<PII > > q;
  for (i=0; i<n; i++) d[i] = INF;
  d[s] = 0;
  q.push(PII(0, s));

  while (q.size()) {
    PII p = q.top();
    q.pop();
    int v = p.second;

    if (d[v] < p.first) continue;

    for (i=0; i<(int)es[v].size(); i++) {
      edge e = es[v][i];
      if (d[e.to] > d[v] + e.cost) {
        d[e.to] = d[v] + e.cost; 
        q.push(PII(d[e.to], e.to));
      }
    }
  }
}

int main() {
  int i, j, k;
  int u, v, c;
  for (i=0; i<V; i++) es[i].clear();

  scanf("%d ", &n);
  for (i=0; i<n; i++) {
    scanf("%d%d ", &u, &k);
    for (j=0; j<k; j++) {
      scanf("%d%d ", &v, &c);
      es[u].psb(edge(u, v, c));
    }
  }

  dijkstra(0);

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

	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 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 (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(int argc, char const* argv[])
{
    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<iostream>
#include<vector>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<string>
#include<sstream>
#include<cmath>
#include<numeric>
#include<map>
#include<stack>
#include<queue>
using namespace std;
int inf = 1000000000;

class node{
public:
  int to;
  int from;
  int cost;
};

int main(void) {

  int n; scanf("%d", &n);
  vector< vector<node> > v(n);
  for(int i=0; i<n; i++){
    int u, k;
    scanf("%d %d", &u, &k);
    for(int j=0; j<k; j++){
      int vv, c;
      scanf("%d %d", &vv, &c);
      node t;
      t.from = u;
      t.to = vv;
      t.cost = c;
      v[u].push_back(t);
    }
  }

  vector<int> dist(n, inf);
  vector<bool> vis(n, false);

  priority_queue< pair<int, int> > pq;
  pq.push(make_pair(0, 0));
  dist[0] = 0;
  vis[0] = true;
  while( !pq.empty() ){
    pair<int, int> pos = pq.top();
    pq.pop();
    int p = pos.second;
    vis[p] = true;
    for(int i=0; i<v[p].size(); i++){
      if( vis[v[p][i].to] ) continue;
      int tmp = dist[v[p][i].from] + v[p][i].cost;
      if( dist[v[p][i].to] <= tmp ) continue;

      dist[v[p][i].to] = tmp;
      pq.push(make_pair(dist[v[p][i].to]*-1, v[p][i].to));

    }

  }

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

  return 0;
}

// EOF