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<vector>
#include<map>
#include<utility>
#include<queue>
using namespace std;

char f[1001][1001];
int d[1001][1001];
int h , w , n , x , y , ans;
typedef pair<int,int> P;
int dx[] = {1,0,-1,0} , dy[] = {0,-1,0,1};

int bfs(int to){
  for( int i = 0 ; i < h ; i++)
    for( int j = 0 ; j < w ; j++)
      d[i][j] = 0;
  queue<P> q;
  q.push(make_pair(x,y));
  d[y][x]=1;
  while(!q.empty()){
    P p = q.front();
    q.pop();
    if(f[p.second][p.first] - '0' == to){
      x = p.first;
      y = p.second;
      break;
    }
    for(int i = 0 ; i < 4 ; i ++){
      int nx = p.first + dx[i], ny = p.second + dy[i];
      if(nx >= 0 && nx < w && ny < h && ny >=0 && d[ny][nx] == 0 && f[ny][nx] != 'X'){
	d[ny][nx] = d[p.second][p.first] + 1;
	q.push(make_pair(nx,ny));
	
      }
    }
  }
  return d[y][x] - 1;
}

C++: #include<cstdio>
#include<iostream>
#include<algorithm>
#include<queue>
#define INF 1000000
using namespace std;
struct data{
    int x,y;
};
int ans[1001][1001],H,W,N,cou;
int dx[]={0,1,0,-1},dy[]={1,0,-1,0};
char field[1001][1001];
int main(){
    data s;
    cin>>H>>W>>N;
    for(int i=0;i<H;i++){
        for(int j=0;j<W;j++){
            cin>>field[i][j];
            if(field[i][j]=='S')s.x=i,s.y=j;
        }
    }
    for(int l=1;l<=N;l++){
        queue<data> q;
        data g;
        for(int i=0;i<H;i++){
            for(int j=0;j<W;j++){
                ans[i][j]=INF;
                if(field[i][j]=='0'+l)g.x=i,g.y=j;
            }
        }
        q.push(s);
        ans[s.x][s.y]=0;
        while(!q.empty()){
            data now;
            now=q.front();
            q.pop();
            if(now.x==g.x&&now.y==g.y)break;
            for(int i=0;i<4;i++){
                if(now.x+dx[i]>=0&&now.x+dx[i]<H&&now.y+dy[i]>=0&&now.y+dy[i]<W&&ans[now.x+dx[i]][now.y+dy[i]]==INF&&field[now.x+dx[i]][now.y+dy[i]]!='X'){
                    data next;
                    next.x=now.x+dx[i],next.y=now.y+dy[i];
                    q.push(next);
                    ans[now.x+dx[i]][now.y+dy[i]]=ans[now.x][now.y]+1;
                }
            }
        }
        cou+=ans[g.x][g.y];
        s=g;
    }
    cout<<cou<<endl;
return 0;
}

C++: #include "bits/stdc++.h"

using namespace std;

//#define int long long

#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define REP(i, n) for (int i = 0; i < (n); i++)

#define pb push_back
#define VDEL(v, n) v.erase(v.begin() + (n))
#define ALL(v) v.begin(), v.end()

#define INTMAX 2147483647
#define INF 200000000
#define TINT(str) atoi(str.c_str())
#define TSTR(num) to_string(num)

typedef long long ll;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<vector<int>> VII;

int dx[4] = {0, 1, 0, -1};
int dy[4] = {1, 0, -1, 0};

PII goal[10];
char k[1000][1000];
int fx, fy;
int H,W;

int BFS(int x, int y)
{
    VII cost;
    cost = VII(H, VI(W, INF));

    cost[fx][fy] = 0;

    queue<PII> q;

    q.push(make_pair(fx, fy));

    while(!q.empty())
    {
        PII now = q.front();
        q.pop();
        int nx = now.first;
        int ny = now.second; 

        REP(i, 4)
        {
            if(nx + dx[i] >= H ||
            nx + dx[i] < 0) continue;
            if(ny + dy[i] >= W || 
            ny + dy[i] < 0) continue;

            if(k[nx + dx[i]][ny + dy[i]] != 'X')
            {
                if(nx + dx[i] == x &&
                    ny + dy[i] == y)
                {
                    return cost[nx][ny] + 1;
                }

                if(cost[nx + dx[i]][ny + dy[i]] > 
                cost[nx][ny])
                {
                    cost[nx + dx[i]][ny + dy[i]] =
                        cost[nx][ny] + 1;
                    q.push(make_pair(nx + dx[i], ny + dy[i]));
                }
            }
            else continue;
        }
    }

    return -1;
}

signed main()
{
    int N;
    cin >> H >> W >> N;

    char str[1001];
    REP(h, H)
    {
        scanf("%s", str);
        REP(w, W)
        {
            k[h][w] = str[w];
            if(k[h][w] == 'S')
            {
                fx = h;
                fy = w;
            }
            if(k[h][w] != '.' &&
                k[h][w] != 'X')
            {
                goal[k[h][w] - '1'] = make_pair(h, w);
            }
        }
    }
    int ans = 0;

    REP(i, N)
    {
        ans += BFS(goal[i].first, goal[i].second);
        fx = goal[i].first;
        fy = goal[i].second;
    }

    cout << ans << endl;

    return 0;
}