Go: ///
// File:  0558.go
// Author: ymiyamoto
//
// Created on Sun Mar  4 20:58:45 2018
//
package main

import (
	"fmt"
	"strconv"
	"strings"
)

type pos struct {
	x, y int
}

var H, W, N int
var graph [][]string

func wfs(p pos, index int) (int, pos) {
	var q []pos
	dists := make([][]int, H)
	for i := range dists {
		dists[i] = make([]int, W)
	}

	q = append(q, p)
	for len(q) > 0 {
		p := q[0]
		dist := dists[p.x][p.y]
		q = q[1:]

		for _, d := range []pos{{-1, 0}, {1, 0}, {0, -1}, {0, 1}} {
			x := p.x + d.x
			y := p.y + d.y
			if 0 <= x && x < H && 0 <= y && y < W && graph[x][y] != "X" && dists[x][y] == 0 {
				dists[x][y] = dist + 1
				q = append(q, pos{x, y})
			}
		}
	}

	for i := range graph {
		for j := range graph[i] {
			if graph[i][j] == strconv.Itoa(index) {
				return dists[i][j], pos{i, j}
			}
		}
	}

	panic("not found")
}

func main() {
	fmt.Scan(&H, &W, &N)

	var start pos

	graph = make([][]string, H)
	for i := range graph {
		var s string
		fmt.Scan(&s)
		graph[i] = strings.Split(s, "")
		for j := range graph[i] {
			if graph[i][j] == "S" {
				start.x = i
				start.y = j
			}
		}
	}

	count := 0
	for i := 1; i <= N; i++ {
		c, s := wfs(start, i)
		start = s
		count += c
	}

	fmt.Println(count)
}

C++: #include<iostream>
#include<map>
#include<queue>
using namespace std;

const int INF = 111111111;
typedef pair<int,int> P;

char m[1500][1500];
int h,w,n,hp,f;
int sx,sy;
int d[1500][1500];
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};

int bfs(){
  queue<P> que;
  for(int i = 0;i < h; i++)
    for(int j = 0;j < w; j++) d[i][j] = INF;

  que.push(P(sx,sy));
  d[sx][sy] = 0;
  hp = 1;

  while(que.size()){
    P p = que.front(); que.pop();

    f = 0;
    for(int i = 0;i < 4; i++){
      int nx = p.first + dx[i], ny = p.second + dy[i];

      int tt = d[p.first][p.second];
      if(0 <= nx && nx < h && 0 <= ny && ny < w && m[nx][ny] != 'X' && d[nx][ny] == INF){
	if(m[nx][ny] >= '1' && m[nx][ny] <= '9'){
	  int t;
	  if(m[nx][ny] == '1') t = 1;
	  else if(m[nx][ny] == '2') t = 2;
	  else if(m[nx][ny] == '3') t = 3;
	  else if(m[nx][ny] == '4') t = 4;
	  else if(m[nx][ny] == '5') t = 5;
	  else if(m[nx][ny] == '6') t = 6;
	  else if(m[nx][ny] == '7') t = 7;
	  else if(m[nx][ny] == '8') t = 8;
	  else if(m[nx][ny] == '9') t = 9;

	  if(t <= hp){
	    n--;
	    hp++;
	    m[nx][ny] = '.';
	    while(que.size()) que.pop();
	    for(int i = 0;i < h; i++)
	      for(int j = 0;j < w; j++) d[i][j] = INF;
	    f = 1;
	  }
	}
	que.push(P(nx,ny));
	d[nx][ny] = tt + 1;
      }
      if(n == 0) return d[nx][ny];
      if(f) break;
    }
  }
}

int main(void){
  cin >> h >> w >> n;
  for(int i = 0;i < h; i++){
    for(int j = 0;j < w; j++){
      cin >> m[i][j];
      if(m[i][j] == 'S'){
	sx = i, sy = j;
      }
    }
  }

  cout << bfs() << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
int main() {
    int Y, X, n;
    int x[10];
    int y[10];
    int ans = 0;
    cin >> Y >> X >> n;
    string a[Y];
    for(int i = 0; i < Y; i++) {
        cin >> a[i];
    }
    int step[Y + 2][X + 2];

    for(int i = 0; i < X + 2; i++) {
        step[0][i] = -2;
    }
    for(int i = 1; i <= Y; i++) {
        step[i][0] = -2;
        for(int j = 1; j <= X; j++) {
            if(a[i - 1][j - 1] == 'S') {
                x[0] = j;
                y[0] = i;
                step[i][j] = 0;
            }
            if(a[i - 1][j - 1] == '.') {
                step[i][j] = -1;
            }
            if(a[i - 1][j - 1] == 'X') {
                step[i][j] = -2;
            }
            if(a[i - 1][j - 1] == '1') {
                x[1] = j;
                y[1] = i;
                step[i][j] = 1;
            }
            if(a[i - 1][j - 1] == '2') {
                x[2] = j;
                y[2] = i;
                step[i][j] = 2;
            }
            if(a[i - 1][j - 1] == '3') {
                x[3] = j;
                y[3] = i;
                step[i][j] = 3;
            }
            if(a[i - 1][j - 1] == '4') {
                x[4] = j;
                y[4] = i;
                step[i][j] = 4;
            }
            if(a[i - 1][j - 1] == '5') {
                x[5] = j;
                y[5] = i;
                step[i][j] = 5;
            }
            if(a[i - 1][j - 1] == '6') {
                x[6] = j;
                y[6] = i;
                step[i][j] = 6;
            }
            if(a[i - 1][j - 1] == '7') {
                x[7] = j;
                y[7] = i;
                step[i][j] = 7;
            }
            if(a[i - 1][j - 1] == '8') {
                x[8] = j;
                y[8] = i;
                step[i][j] = 8;
            }
            if(a[i - 1][j - 1] == '9') {
                x[9] = j;
                y[9] = i;
                step[i][j] = 9;
            }
        }
        step[i][X + 1] = -2;
    }
    for(int i = 0; i < X + 2; i++) {
        step[Y + 1][i] = -2;
    }

    queue<pair<int, int> > q;

    q.push(make_pair(y[0], x[0]));

    for(int i = 0; i < n; i++) {
        while(q.empty() == false) {
            if(q.front().first == y[i + 1] && q.front().second == x[i + 1]) {
                ans += step[y[i + 1]][x[i + 1]];
                for(int j = 1; j <= Y; j++) {
                    for(int k = 1; k <= X; k++) {
                        step[j][k] = -1;
                    }
                }
                break;
            }
            if(step[q.front().first + 1][q.front().second] != -2) {
                step[q.front().first + 1][q.front().second] =
                    step[q.front().first][q.front().second] + 1;
                q.push(make_pair(q.front().first + 1, q.front().second));
            }
            if(step[q.front().first - 1][q.front().second] != -2) {
                step[q.front().first - 1][q.front().second] =
                    step[q.front().first][q.front().second] + 1;
                q.push(make_pair(q.front().first - 1, q.front().second));
            }
            if(step[q.front().first][q.front().second + 1] != -2) {
                step[q.front().first][q.front().second + 1] =
                    step[q.front().first][q.front().second] + 1;
                q.push(make_pair(q.front().first, q.front().second + 1));
            }
            if(step[q.front().first][q.front().second - 1] != -2) {
                step[q.front().first][q.front().second - 1] =
                    step[q.front().first][q.front().second] + 1;
                q.push(make_pair(q.front().first, q.front().second - 1));
            }
            q.pop();
        }
    }
    cout << ans << endl;
    return 0;
}