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<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> P;
#define pb push_back
#define fi first
#define se second

#define MAX_V 110
#define INF 1e9

struct edge{int to,cost;};
typedef pair<int,int> P;
int d[MAX_V];
int V;
vector<edge> G[MAX_V];

edge makeedge(int t,int c){
    edge e;
    e.to=t;
    e.cost=c;
    return e;
}

void addedge(int s,int t,int c){
    G[s].push_back(makeedge(t,c));
    //G[t].push_back(makeedge(s,cost));
}

void dijkstra(int s){
    priority_queue<P, vector<P>, greater<P> > que;
    fill(d,d+V,INF);
    d[s]=0;
    que.push(P(0,s)); 

    while(!que.empty()){
        P p=que.top(); que.pop();
        int v=p.second;
        if(d[v]<p.first) continue;
        for(int i=0;i<G[v].size();i++){
            edge &e=G[v][i];
            if(d[e.to]>d[v]+e.cost){
                d[e.to]=d[v]+e.cost;
                que.push(P(d[e.to],e.to));
            }
        }
    }
}


int main(){
    int i,j,n;
    cin>>n;
    V=n;
    int u,k;
    int x,y;
    for(i=0;i<n;i++){
        cin>>u>>k;
        for(j=0;j<k;j++){
            cin>>x>>y;
            addedge(i,x,y);
        }
    }
    dijkstra(0);
    for(i=0;i<n;i++){
        cout<<i<<" "<<d[i]<<endl;
    }
    return 0;
}

C++: #include <iostream>
#include <iomanip>
#include <algorithm>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <functional>
#include <sstream>
#include <string>
#include <utility>
#include <map>
#include <memory>
#include <set>
#include <vector>
#include <deque>
#include <list>
#include <stack>
#include <queue>

using namespace std;

class SSSPath
{
public:
  vector<int> v;
  int solve();
};

int SSSPath::solve()
{
  int n;
  cin >> n;

  const int infty = 20000;
  vector<int> d( n, infty );
  
  d[0] = 0;

  vector<vector<int>> adj( n, vector<int>( n, -1 ) );


  for ( auto i = 0; i < n; ++i )
    {
      int u, v, k, c;
      cin >> u >> k;
      for ( auto j = 0; j < k; ++j )
        {
          cin >> v >> c;
          adj[u][v] = c;
        }
    }

  vector<int> sv( n, true );

  while ( true )
    {
      int md = infty;
      int u;
      
      for ( auto i = 0; i < n; ++i )
        {
          if ( sv[i] && d[i] < md )
            {
              u = i;
              md = d[i];
            }
        }

      if ( md == infty ) break;

      sv[u] = false;
      
      for ( auto i = 0; i < n; ++i )
        {
          if ( sv[i] && adj[u][i] >= 0 )
            {
              if ( d[u] + adj[u][i] < d[i] )
                {
                  d[i] = d[u] + adj[u][i];
                  
                }
            }
          
        }
    }

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

int main()
{
  SSSPath s;

  s.solve();

  return 0;
}

C++: // -*- mode:c++; coding:utf-8; c-basic-offset:2; -*-
// ALDS1_12_B: Single Source Shortest Path I

#include <algorithm>
#include <cstdio>

using uint = unsigned int;

class Graph {
  const uint n_;
  uint* const g_;
  const uint INFINIT;
  
public:

  Graph(uint n) : n_(n), g_(new uint[(n_*n_)]), INFINIT(100000*(n_-1)+1) {
    std::fill_n(g_, (n_*n_), INFINIT);
  }

  ~Graph() { delete[] g_; }
  
  uint* operator [](uint i) const { return g_+(n_*i); }

  void dijkstra(uint* dist)
  {
    std::fill_n(dist, n_, INFINIT);
    bool visited[n_];
    std::fill_n(visited, n_, false);
    auto i = 0u; // 0-start
    visited[i] = true;
    dist[i] = 0u;
    for (auto n = 0u; n < n_-1; ++n) {
      auto cur_min = INFINIT;
      auto es = (*this)[i];
      auto base_dist = dist[i];
      for (auto j = 0u; j < n_; ++j) {
        if (visited[j]) continue;
        dist[j] = std::min(dist[j], base_dist+es[j]);
        if (cur_min > dist[j]) {
          cur_min = dist[j];
          i = j;
        }
      }
      visited[i] = true;
    }
  }
};

int main()
{
  uint n;
  std::scanf("%u", &n);

  Graph g(n);

  uint u, k, v, c;
  for (auto i = 0u; i < n; ++i) {
    std::scanf("%u %u", &u, &k);
    for (auto j = 0u; j < k; ++j) {
      std::scanf("%u %u", &v, &c);
      g[u][v] = c;
    }
  }

  uint dist[n];
  g.dijkstra(dist);
  for (auto i = 0u; i < n; ++i) {
    std::printf("%u %u\n", i, dist[i]);
  }
}

// eof

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

using namespace std;

int n;
typedef pair<int, int> P;
const int N = 110;
vector<P> G[N];
int dis[N];
bool vis[N];

void dijkstra() {
    memset(vis, false, sizeof(vis));
    for (int i = 0; i < n; i++) dis[i] = INT_MAX;
    priority_queue<P, vector<P>, greater<P>> heap;
    heap.push({0, 0});
    dis[0] = 0;

    while (!heap.empty()) {
        int u = heap.top().second, cost = heap.top().first;
        heap.pop();
        if (vis[u]) continue;
        vis[u] = true;
        for (int i = 0; i < G[u].size(); i++) {
            int v = G[u][i].second, len = G[u][i].first;
            if (!vis[v] && dis[u] + len < dis[v]) {
                dis[v] = dis[u] + len;
                heap.push({dis[v], v});
            }
        }
    }
}

int main() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        int u, k;
        cin >> u >> k;
        int v, c;
        for (int j = 0; j < k; j++) {
            cin >> v >> c;
            G[u].push_back({c, v});
        }
    }

    dijkstra();

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

    return 0;
}