Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Node struct {
	cost int
	done bool
}

type Edge struct {
	to, cost int
}

const INF = 1 << 60

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	nodes := make([]Node, N)
	for i := 0; i < N; i++ {
		nodes[i].cost = INF
	}
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id] = append(E[id], Edge{to, cost})
		}
	}
	nodes[0].cost = 0
	for {
		cur := 0
		minCost := INF
		for i := 0; i < N; i++ {
			n := nodes[i]
			if !n.done && n.cost < minCost {
				cur = i
				minCost = n.cost
			}
		}
		if minCost == INF {
			break
		}
		nodes[cur].done = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+nodes[cur].cost
			if !nodes[to].done && cost < nodes[to].cost {
				nodes[to].cost = cost
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, nodes[i].cost)
	}
	wtr.Flush()
}

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 (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;
    
    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>
using namespace std;

typedef struct NODE {
    int id;
    int degree;
    int min_cost;
    bool done;
    vector<int> adj_n;
    vector<int> cost_to_n;
} node;

node **nodes;
int n;

node *gen_node(int id, int degree, vector<int> adj_n, vector<int> cost_to_n) {
    node *p = (node *)malloc(sizeof(node));
    p->id = id;
    p->degree = degree;
    if (id != 0) {
        p->min_cost = 100010;
    } else {
        p->min_cost = 0;
    }

    p->done = false;
    p->adj_n = adj_n;
    p->cost_to_n = cost_to_n;
    return p;
}

void solve() {
    for (int i = 0; i < n; i++) {
        node *src = (node *)malloc(sizeof(node));
        src = nodes[i];
        for (int j = 0; j < src->degree; j++) {
            node *dst = (node *)malloc(sizeof(node));
            dst = nodes[src->adj_n[j]];

            // 最小コストの更新
            //cout << "src: " << src->id << " dst: " << dst->id;
            //cout << " dst's min cost: " << dst->min_cost << " src's cost to dst: " << src->min_cost + src->cost_to_n[j] << endl;
            dst->min_cost = min(dst->min_cost, src->min_cost + src->cost_to_n[j]);

            // // dstの隣接nodeからsrcを消す処理
            // auto itr = find(dst->adj_n.begin(), dst->adj_n.end(), src->id);
            // int erase_index = itr - dst->adj_n.begin();
            // dst->degree--;
            // dst->adj_n.erase(dst->adj_n.begin() + erase_index);
            // dst->cost_to_n.erase(dst->cost_to_n.begin() + erase_index);
        }
    }
}

void print_node() {
    for (int i = 0; i < n; i++) {
        cout << nodes[i]->id << " " << nodes[i]->min_cost << endl;
    }
}

int main() {
    int u, k;
    cin >> n;

    nodes = (node **)malloc(sizeof(node) * n);

    for (int i = 0; i < n; i++) {
        cin >> u >> k;
        vector<int> adj_n;
        vector<int> cost_to_n;

        int node_tmp;
        int cost_tmp;
        for (int j = 0; j < k; j++) {
            cin >> node_tmp >> cost_tmp;
            adj_n.push_back(node_tmp);
            cost_to_n.push_back(cost_tmp);
        }
        node *p = gen_node(u, k, adj_n, cost_to_n);
        nodes[u] = p;
    }

    solve();
    solve();

    print_node();

    return 0;
}

C++: #include <iostream>
#include <vector>
using namespace std;
struct edge {int from, to, cost;};
const long long INF = 1000000000;
void bellman_ford(std::vector<edge> & es, std::vector<int> & d, int E, int V, int s) {
  for(int i=0;i<V;i++) d[i] = INF;
  d[s] = 0;
  while(true) {
    bool update = false;
    for(int i=0;i<E;i++) {
      edge e = es[i];
      if(d[e.from] != INF && d[e.to] > d[e.from] + e.cost) {
        d[e.to] = d[e.from] + e.cost;
        update = true;
      }
    }
    if(!update) break;
  }
}
 
int main() {
  int n;
  cin >> n;
  vector<edge> e;
  for(int i=0;i<n;i++) {
    int u, k;
    cin >> u >> k;
    for(int j=0;j<k;j++) {
      int vi, ci;
      cin >> vi >> ci;
      edge ei = {u, vi, ci};
      e.push_back(ei);
    }
  }
  vector<int> d(n);
  bellman_ford(e, d, e.size(), n, 0);
  for(int i=0;i<n;i++) {
    cout << i << " " << d[i] << endl;
  }

}