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 <algorithm>
#include <string>
#include <vector>
#include <map>
#include <sstream>
#include <functional>
#include <numeric>
#include <cmath>
#include <cstring>
#include <cstdio>
#include <queue>
#include <stack>
#include <set>

using namespace std;

#define ALL(co) co.begin(), co.end()
#define tpl(...) make_tuple(__VA_ARGS__)

typedef long long LL;
typedef pair<int, int> P; typedef pair<P, int> PI; typedef pair<P, P> PP;
typedef vector<int> Array; typedef vector<vector<int> > Array2;
typedef vector<LL> LArray; typedef vector<P> PArray; typedef vector<string> SArray;

const int INF = 1 << 29;
const LL LINF = 1LL << 60;

inline int getInt() { int itiv; return (cin >> itiv, itiv); }
template <typename T> void readAll(vector<T>& vec) { for (int i = 0, size = vec.size(); i < size; i++) cin >> vec[i]; }
template <typename T, typename U> void readAll(vector<pair<T, U> >& vec) { for (int i = 0, size = vec.size(); i < size; i++) cin >> vec[i].first >> vec[i].second; }
template < typename T > inline string toString( const T &a ){ ostringstream oss; oss << a; return oss.str(); };
inline bool between(int min, int max, int n) { return min <= n && n <= max; }
inline bool inRange(int begin, int end, int n) { return begin <= n && n < end; }
inline bool inRange(int size, int n) { return 0 <= n && n < size; }

int dx[] = { -1, 0, 1, 0 }, dy[] = { 0, -1, 0, 1 };
int dr[] = { 0, -1, 0, 1 }, dc[] = { -1, 0, 1, 0 };
bool visited[1000][1000];
char stage[1000][1000];
int h, w, n;

int main(void)
{
	ios::sync_with_stdio(false);
	while(cin >> h >> w >> n && n)
	{
		PArray goals(n + 1);
		for (int i = 0; i < h; i++)
		{
			for (int j = 0; j < w; j++)
			{
				cin >> stage[i][j];
				if(stage[i][j] == 'S') goals[0] = P(i, j);
				int num = stage[i][j] - '0';
				if(inRange(n + 1, num)) goals[num] = P(i, j);
			}
		}

		/*int ans = 0;
		for (int i = 0; i < n; i++)
		{
			P start = goals[i], goal = goals[i + 1];
			memset(visited, false, sizeof(visited));
			queue<PI> que;
			que.push(PI(start, 0));
			while (!que.empty())
			{
				PI pi = que.front(); que.pop();
				if(goal == pi.first)
				{
					ans += pi.second;
					break;
				}
				int r = pi.first.first, c = pi.first.second;
				visited[r][c] = true;

				for (int i = 0; i < 4; i++)
				{
					int nr = r + dr[i], nc = c + dc[i];
					if(!inRange(h, nr) || !inRange(w, nc) || stage[nr][nc] == 'X' || visited[nr][nc]) continue;
					que.push(PI(P(nr, nc), pi.second + 1));
				}
			}
		}
		cout << ans << endl;*/
	}
	return 0;
}

C++: #include <iostream>
#include <queue>
#include <cstring>
#include <string>
using namespace std;
struct point{
	int x;
	int y;
};
const int MAX = 10000000;
int h,w,n,c[1001][1001];
char board[1002][1002],tboard[1002][1002];
int bfs(int y,int x){
	int dx[] = {0,-1,1,0},dy[] = {-1,0,0,1},tx,ty,t = 1,min = 0;
	queue<point> que;
	point p,tp;
	c[y][x] = 0; 
	p.x = x;
	p.y = y;
	que.push(p);
	while(!que.empty()){
		p = que.front();
		que.pop();
		for(int i = 0;i < 4;++i){
			tx = p.x + dx[i];
			ty = p.y + dy[i];
			tp.x = tx;
			tp.y = ty;
			if(board[ty][tx] == '\0') continue;
			if(board[ty][tx] != '.' && board[ty][tx] != 'X'){	
				if(board[ty][tx] - '0' == t){	
					min += c[p.y][p.x] + 1;
					if(board[ty][tx] - '0' == n){
						return min;
					}
					for(int j = 1;j <= h;++j){
						for(int k = 1;k <= w;++k){
							c[j][k] = MAX;
						}
					}
					++t;
					while(!que.empty()){
						que.pop();
					}
					c[ty][tx] = 0;
					que.push(tp);
					break;
				}
			}
			if(board[ty][tx] == '.' && c[ty][tx] == MAX){
				c[ty][tx] = c[p.y][p.x] + 1;
				que.push(tp);
			}	
		}
	}
	return 0;
}
int main(){
	int x,y;
	string str;
	memset(board,'0',sizeof(char));
	for(int i = 0;i < 1001;++i){
		for(int j = 0;j < 1001;++j){
			c[i][j] = MAX;
		}
	}
	cin >> h >> w >> n;
	for(int i = 0;i < h;++i){
		cin >> str;
		for(int j = 0;j < w;++j){
			board[i+1][j+1] = tboard[i+1][j+1] = str[j];
			if(str[j] == 'S'){
				x = j + 1;
				y = i + 1;
			}
		}
	}
	cout << bfs(y,x) << 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;
					}
				}
			}
			else{

			}
		}
	}
}


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;
}