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)
}

Python: 
def getStart(field):
    search_field = field[1:]     # cut the first [H,W,N] for min_path matrix
    for y in range(len(search_field)):
        for x in range(len(search_field[0])):
            if search_field[y][x] == "S":
                return x,y+1


def bfs(field,start_x,start_y,goal_N):
    direction = [[-1,0],[1,0],[0,-1],[0,1]]
    gotten_cheese = 1
    distance = 0
    que = []
    que.append([start_x,start_y,gotten_cheese,distance])
    INF = 1
    min_path = [[INF for j in range(field[0][1])] for i in range(field[0][0])]
    while len(que) != 0:
        current = que.pop(0)
        for d in direction:
            nx = current[0] + d[0]
            ny = current[1] + d[1]
            if 0 <= nx < field[0][1] and 1 <= ny < field[0][0]+1 and field[ny][nx] != "X" and min_path[ny-1][nx] == INF:
                if field[ny][nx] == current[2]: # at the same cheese-power number
                    if field[ny][nx] == goal_N: # goal
                        print(current[3]+1)
                        return
                    else: # not goal, but could eat cheese
                        que = []
                        que.append([nx,ny,current[2]+1,current[3]+1])
                        min_path = [[INF for j in range(field[0][1])] for i in range(field[0][0])]
                        break
                else:
                    que.append([nx,ny,current[2],current[3]+1])
                    min_path[ny-1][nx] = 0


def main(field):

    # field = [[10,10,9],
    # [".","X",".",".",".","X",".","S",".","X"],
    # [6,".",".",5,"X",".",".","X",1,"X"],
    # [".",".",".","X","X","X","X",".",".","X"],
    # ["X",".",".",9,"X",".",".",".","X","."],
    # [8,".","X",2,"X",".",".","X",3,"X"],
    # [".",".",".","X","X",".","X",4,".","."],
    # ["X","X",".",".",".",".",7,"X",".","."],
    # ["X",".",".","X",".",".","X","X",".","."],
    # ["X",".",".",".","X",".","X","X",".","."],
    # [".",".","X",".",".",".",".",".",".","."]]

    sx,sy = getStart(field)
    bfs(field,sx,sy,field[0][2])

f = []
while True:
    row = input().split()
    for i in range(len(row)):
        try:
            row[i] = int(row[i])
        except:
            continue
    field.append(row)
    if len(f) == field[0][0] + 1:
        main(f)
        break



# matrix = []
# while True:
#     row = input().rstrip().split()
#     if len(row) == 3:
#         re_row = []
#         for i in row:
#             re_row.append(int(i))
#         matrix.append(re_row)
#     else:
#         re_row = []
#         for char in row[0]:
#             if char.isdigit():
#                 re_row.append(int(char))
#             else:
#                 re_row.append(char)
#         matrix.append(re_row)
#     if len(matrix) == int(matrix[0][0]) + 1:
#         main(matrix)
#         break

Python: def bfs(field,H,W,start_x,start_y,tmp_N):
    direction = [[-1,0],[1,0],[0,-1],[0,1]]
    que = []
    que.append([start_x,start_y])
    INF = 1000000
    min_path = [[INF] * W for i in range(H)]
    min_path[start_y][start_x] = 0
    while len(que) != 0:
        current = que.pop(0)
        for d in direction:
            nx = current[0] + d[0]
            ny = current[1] + d[1]
            if 0 <= nx < W and 0 <= ny < H and field[ny][nx] != "X" and min_path[ny][nx] == INF:
                min_path[ny][nx] = min_path[current[1]][current[0]] + 1
                if field[ny][nx] == tmp_N:
                    return nx,ny,min_path[ny][nx]
                else:
                    que.append([nx,ny])

def getField():
    matrix = []
    first = input().strip()
    H,W,N = map(int,first.split())
    for i in range(H):
        row = list(input().strip())
        for j in range(W):
            if row[j].isdigit():
                row[j] = int(row[j])
        matrix.append(row)
    return matrix,H,W,N

def getStart(field):
    for y in range(len(field)):
        for x in range(len(field[0])):
            if field[y][x] == "S":
                return x,y

def main():
    matrix,H,W,N = getField()
    sx,sy = getStart(matrix)
    distance = 0
    tmp_x,tmp_y,tmp_dist = bfs(matrix,H,W,sx,sy,1)
    distance += tmp_dist
    tmps = [tmp_x,tmp_y]
    for k in range(N-1):
        tmp_x,tmp_y,tmp_dist = bfs(matrix,H,W,tmps[0],tmps[1],k+2)
        distance += tmp_dist
        tmps = [tmp_x,tmp_y]
    print(distance)

if __name__=='__main__':
    main()

Python: # directions
x_dir = [0, 1, 0, -1]
y_dir = [1, 0, -1, 0]

# map info
visited = []
maps = []

# bfs algorithm
def bfs(h, w, cheese, sx, sy, moves):
    que = [(moves, sx, sy)]

    for i in range(h):
        for j in range(w):
            visited[i][j] = (maps[i][j] != 'X')

    visited[sy][sx] = False

    while len(que) > 0:
        c_moves, c_x, c_y = que.pop(0)
        if maps[c_y][c_x] == cheese:
            return (c_moves, c_x, c_y)

        for i in range(4):
            n_x = c_x + x_dir[i]
            n_y = c_y + y_dir[i]

            if(0 <= n_x < w and 0 <= n_y < h and visited[n_y][n_x]):
                que.append((c_moves+1, n_x, n_y))
                visited[n_y][n_x] = False

    return (-1, -1, -1)

# main function
if __name__ == '__main__':
    inputs = (input()).split()

    H = int(inputs[0])
    W = int(inputs[1])
    N = int(inputs[2])

    visited = [[True for i in range(W)] for j in range(H)]
    maps = ["" for i in range(H)]

    x, y = 0, 0
    for i in range(H):
        maps[i] = input()
        for j in range(W):
            if maps[i][j] == 'S':
                x, y = j, i

    moves = 0
    for i in range(1, N+1, 1):
        moves, x, y = bfs(H, W, str(i), x, y, moves)

    print(str(moves))

Python: from collections import deque

h, w, n = map(int, input().split())
g = ['0'] * h

sx, sy = -1, -1
pos = -1
for i in range(h):
    g[i] = input()
    if pos == -1:
        pos = g[i].find('S')
        if pos != -1:
            sx = i
            sy = pos

book = set()
queue = deque()

ans = 0

Next = [[-1, 0], [1, 0], [0, -1], [0, 1]]

for a in range(1, n + 1):
    book.clear()
    queue.clear()
    queue.append((sx, sy, 0))
    aim = str(a)

    while len(queue):
        t = queue.popleft()
        if (t[0], t[1]) in book:
            continue

        if g[t[0]][t[1]] == aim:
            ans += t[2]
            # print(t[0], ' ', t[1], ' ', aim, ' ', ans)
            sx, sy = t[0], t[1]
            break

        book.add((t[0], t[1]))
        for i in range(4):
            tx = t[0] + Next[i][0]
            ty = t[1] + Next[i][1]
            if 0 <= tx < h and 0 <= ty < w and g[tx][ty] != 'X':
                queue.append((tx, ty, t[2] + 1))

print(ans)