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<stdio.h>
#include<iostream>
#include<queue>
#include<string.h>
using namespace std;
int map[1002][1002], was[1002][1002];
int main(void)
{
	int count = 0, H, W, N, i, j;
	char c=0;
	pair<int, int> q,a[10];
	queue<pair<int, int> > que;
	queue<int> quec;
	quec.push(0);
	scanf("%d %d %d", &H, &W, &N);
	for (i = 0; i <= H + 1; i++)
	{
		map[i][0] = -1;
		map[i][W + 1] = -1;
		was[i][0] = -1;					/*?????????????£???????(???)*/
		was[i][W + 1] = -1;
	}
	for (j = 1; j <= W; j++)
	{
		map[0][j] = -1;
		map[H + 1][j] = -1;           /*?????????????£???????????¨????*/
		was[0][j] = -1;
		was[H + 1][j] = -1;
	}
	for (i = 1; i <= H; i++)
	{
		for (j = 1; j <= W; j++)			/*???????????????(??????????????°???????????????????????????????????¨??°??????????????????*/
		{
			cin >> c;
			if (c == 'X')
				map[i][j] = -1;
			if (c == 'S')
			{
				q.first = i;
				q.second = j;
			}
			if (c == '1')
			{
				a[1].first = i;
				a[1].second = j;
			}
			if (c == '2')
			{
				a[2].first = i;
				a[2].second = j;
			}
			if (c == '3')
			{
				a[3].first = i;
				a[3].second = j;
			}
			if (c == '4')
			{
				a[4].first = i;
				a[4].second = j;
			}
			if (c == '5')
			{
				a[5].first = i;
				a[5].second = j;
			}
			if (c == '6')
			{
				a[6].first = i;
				a[6].second = j;
			}
			if (c == '7')
			{
				a[7].first = i;
				a[7].second = j;
			}
			if (c == '8')
			{
				a[8].first = i;
				a[8].second = j;
			}
			if (c == '9')
			{
				a[9].first = i;
				a[9].second = j;
			}
		}
	}
	/*for (int i = 1; i <= H; i++) {
		for (int j = 1; j <= W; j++) {
			cout << map[i][j];
		}
		cout << endl;
	}*/
	que.push(q);
	i = 1;
	while (i <= N)
	{
		count = quec.front();
		quec.pop();
		q = que.front();
		que.pop();

		if (q == a[i])
		{

			i++;
			memset(was, 0, sizeof(was));
			while (!que.empty())
				que.pop();
			while (!quec.empty())
				quec.pop();
			quec.push(count);
			que.push(q);
			continue;
		}
		if (map[q.first][q.second + 1] != -1 && was[q.first][q.second + 1] != -1)
		{
			was[q.first][q.second+1] = -1;
			q.second++;
			que.push(q);					/*???????????????*/
			count++;
			quec.push(count);
			count--;
			q.second--;
		}
		if (map[q.first][q.second - 1] != -1 && was[q.first][q.second-1] != -1)
		{
			was[q.first][q.second-1] = -1;
			q.second--;
			que.push(q);
			count++;						/*???????????????*/
			quec.push(count);
			count--;
			q.second++;
		}
		if (map[q.first + 1][q.second] != -1 && was[q.first + 1][q.second] != -1)
		{
			was[q.first + 1][q.second] = -1;
			q.first++;
			que.push(q);
			count++;						/*???????????????*/
			quec.push(count);
			count--;
			q.first--;
		}
		if (map[q.first - 1][q.second] != -1 && was[q.first - 1][q.second] != -1)
		{
			was[q.first-1][q.second] = -1;
			q.first--;
			que.push(q);
			count++;							/*???????????????*/
			quec.push(count);
			count--;
			q.first++;
		}
	}

	printf("%d\n", count);					/*????????£???????????????????¨??????????*/
	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); i++)
#define shosu(n) setprecision(n)
#define INF 999999999
using namespace std;
int h, w, n;
string data[1100];
int main() {
  while (cin >> h >> w >> n) {
    rep(i, h) cin >> data[i];
    pair<int, int> ce[10];
    rep(i, h) rep(j, w) {
      if (data[i][j] == 'S') {
        ce[0] = pair<int, int>(i, j);
      }
      if (isdigit(data[i][j])) {
        ce[data[i][j] - '0'] = pair<int, int>(i, j);
      }
    }
    int sum = 0;
    rep(i, n) {
      int mp[1100][1100];
      rep(i, 1100) rep(j, 1100) mp[i][j] = INF;
      bool used[1100][1100] = {};

      mp[ce[i].first][ce[i].second] = 0;
      used[ce[i].first][ce[i].second] = true;
      queue<pair<int, int>> que;
      que.push(ce[i]);
      while (que.size()) {
        int y = que.front().first;
        int x = que.front().second;
        que.pop();
        int dx[] = {0, 1, 0, -1};
        int dy[] = {1, 0, -1, 0};
        rep(i, 4) {
          int ddy = y + dy[i];
          int ddx = x + dx[i];
          if (ddy >= 0 && ddy < h && ddx >= 0 && ddx < w &&
              data[ddy][ddx] != 'X' && !used[ddy][ddx]) {
            used[ddy][ddx] = true;
            mp[ddy][ddx] = mp[y][x] + 1;
            que.push(pair<int, int>(ddy, ddx));
          }
        }
      }
      sum += mp[ce[i + 1].first][ce[i + 1].second];
    }
    cout << sum << endl;
  }

  return 0;
}

C++: //#include "stdafx.h"
#include <iostream>
#include <queue>
#include <cstring>

using namespace std;

int row, col, n;

typedef struct point {
	int x, y;
};

char map[1000][1000];
int d[1000][1000];
int direct[4][2] = { {0,1},{0,-1},{1,0},{-1,0} };

int BFS(int &startX, int &startY, char target) {
	memset(d, 0, sizeof(d));

	queue<point> q;
	point p;
	p.x = startX;
	p.y = startY;

	q.push(p);
	while (!q.empty()) {
		int nowX = q.front().x,nowY = q.front().y;
		q.pop();

		if (map[nowX][nowY] == target) {
			startX = nowX;
			startY = nowY;
			return d[nowX][nowY];
		}

		int nextX, nextY;
		for (int i = 0; i < 4; i++) {
			nextX = nowX + direct[i][0];
			nextY = nowY + direct[i][1];

			if (nextX >= 0 && nextY >= 0 && nextX < row && nextY < col && 
					map[nextX][nextY] != 'X' && d[nextX][nextY] == 0) {
				d[nextX][nextY] = d[nowX][nowY] + 1;
				p.x = nextX;
				p.y = nextY;
				q.push(p);
			}
		}
	}
	return -1;
}

int main() {
	int startX, startY, sum = 0;

	cin >> row >> col >> n;
	for (int i = 0; i < row; i++) {
		cin >> map[i];
		for (int j = 0; j < col; j++) {
			if (map[i][j] == 'S') {
				startX = i;
				startY = j;
			}
		}
	}

	for (int i = 0; i < n; i++) {
		int dis = BFS(startX, startY, i + '1');

		if (dis == -1)cout << "error" << endl;
		else sum += dis;
	}
	cout << sum << endl;
}