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 "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)

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

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)
{
    int cost[1000][1000];

    REP(i, H)
    {
        REP(h, W)
        {
            cost[i][h] = 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(nx + dx[i] == x &&
            ny + dy[i] == y)
            {
                return cost[nx][ny] + 1;
            }

            if(k[nx + dx[i]][ny + dy[i]] != 'X')
            {
                if(cost[nx + dx[i]][ny + dy[i]] > 
                cost[nx][ny])
                {
                    cost[nx + dx[i]][ny + dy[i]] =
                        cost[nx][ny] + 1;
                    q.push({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;
}

C++: #include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <queue>

#define INF (1e+9)
#define LLINF (1e+18)
#define LL long long

using namespace std;

typedef struct info{
	int nx;
	int ny;
	int cost;
	int target;
	info(int a,int b,int c,int d){
		nx = a;
		ny = b;
		cost = c;
		target = d;
	}
}info;

bool isNumChar(char c){
	if((0 <= c-48)&&(c-48 <= 9))return true;
	return false;
}

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

int W,H;
int N;

int sx[16] = {0};
int sy[16] = {0};

char field[1024][1024] = {""};
int record[1024][1024][12] = {0};
bool flag[16] = {false};

queue<info> que;


int ans;



int recordReset(){
	for(int i = 0;i < 1024;i++){
		for(int j = 0;j < 1024;j++){
			for(int k = 0;k < 16;k++){
				record[i][j][k] = INF;
			}
		}
	}
}

int bfs(){
	info now(0,0,0,0);
	info next(0,0,0,0);
	for(int i = 0;i < N;i++){
		next = info(sx[i],sy[i],0,i+1);
		que.push(next);
	}

	recordReset();
	while(!que.empty()){
		now = que.front();
		que.pop();
		if(!flag[now.target]){
			//printf("###(%d,%d):::cost<%d>:::target<%d>\n",now.nx,now.ny,now.cost,now.target);
			if(record[now.nx][now.ny][now.target] > now.cost){
				record[now.nx][now.ny][now.target] = now.cost;
				if((sx[now.target] == now.nx)&&(sy[now.target] == now.ny)){
					flag[now.target] = true;
					//printf("###target<%d> completed\n",now.target);
					ans += record[now.nx][now.ny][now.target];
				}
				else{
					switch(field[now.nx][now.ny]){
					case 'X':
						break;
					default:
						for(int i = 0;i < 4;i++){
							next = info(now.nx + dx[i],now.ny + dy[i],now.cost + 1,now.target);
							que.push(next);
						}
						break;
					}
				}
			}
		}
	}
}


int main (void){
	//while(true){
		scanf("%d%d",&H,&W);
		scanf("%d",&N);
		//if((W == 0)&&(H == 0))break;

		ans = 0;

		//Reset Field
		for(int i = 0;i < 1024;i++){
			for(int j = 0;j < 1024;j++){
				field[j][i] = 'X';
			}
		}

		//Reset Flag
		for(int i = 0;i < 16;i++){
			flag[i] = false;
		}

		//Reading Data
		for(int i = 1;i <= H;i++){
			scanf(" ");
			for(int j = 1;j <= W;j++){
				scanf("%c",&field[j][i]);
				if(isNumChar(field[j][i])){
					sx[field[j][i]-48] = j;
					sy[field[j][i]-48] = i;
					//printf("###<%d>(%d,%d)\n",field[j][i] - 48,sx[field[j][i] - 48],sy[field[j][i] - 48]);

				}
				else if(field[j][i] == 'S'){
					sx[0] = j;
					sy[0] = i;
					//printf("###<S>(%d,%d)\n",j,i);
				}
			}
		}

		//DBG
		/*for(int i = 0;i < N;i++){
			printf("<%d>(%d,%d)\n",i,sx[i],sy[i]);
		}*/

		//bfs();

		printf("%d\n",ans);
	//}

	return 0;
}