CSES - Aalto Competitive Programming 2026 - wk2 - Mon

Submission details
Task:	Abandoned warehouse
Sender:	aalto26bm_010
Submission time:	2026-09-07 17:28:09 +0300
Language:	Python3 (PyPy3)
Status:	READY
Result:	WRONG ANSWER

Test results
test	verdict	time
#1	ACCEPTED	0.04 s	details
#2	ACCEPTED	0.04 s	details
#3	WRONG ANSWER	0.04 s	details
#4	ACCEPTED	0.04 s	details
#5	WRONG ANSWER	0.04 s	details
#6	ACCEPTED	0.11 s	details
#7	RUNTIME ERROR	0.22 s	details
#8	RUNTIME ERROR	0.19 s	details
#9	RUNTIME ERROR	0.19 s	details
#10	RUNTIME ERROR	0.17 s	details
#11	RUNTIME ERROR	0.06 s	details
#12	RUNTIME ERROR	0.10 s	details
#13	RUNTIME ERROR	0.17 s	details
#14	ACCEPTED	0.04 s	details
#15	ACCEPTED	0.04 s	details
#16	RUNTIME ERROR	0.17 s	details

Code



import math
n, m = input().split()
n = int(n); m = int(m)


map = [[] for _ in range(m)]
CHAR = {"#":1, ".":0, "A":0, "B":0}

start = None
endd = None
for i in range (n):
    s = input()

    line = [CHAR[c] for c in s]
    map[i] = line
    idx = s.find("A")
    if idx != -1:
        start = (i, idx)
    idxB = s.find("B")
    if idxB != -1:
        endd = (i, idxB)

# print(start, endd)

if start is None or endd is None:
    print("NO")
    exit(0)

visited = set()
ei, ej = endd

def dfs(i, j):
    if (i,j) in visited:
        return -1
    visited.add((i,j))
    if not (0 <= i < n) or  not(0<= j < m):
        return -1
    if map[i][j] == 1:
        return -1
    # print(i,j)
    


    if i == ei and j == ej:
        return ""

    s = dfs(i, j+1)
    if s != -1: return "R" + s
    s = dfs(i, j-1)
    if s != -1: return "L" + s
    s = dfs(i+1, j)
    if s != -1: return "D" + s
    s = dfs(i-1, j)
    if s != -1: return "U" + s


    return -1

si, sj = start
out = dfs(si, sj)

if out == -1:
    print("NO")
else:

    print("YES")
    print(len(out))
    print(out)

Test details

Test 1

Verdict: ACCEPTED

input
`10 10 ##.A###### #.##.##.## #####..### .######### ...` view save

correct output
`NO` view save

user output
`NO` view save

Test 2

Verdict: ACCEPTED

input
`10 10 B#..##.#.. #....A##.. #.....#..# .#......#. ...` view save

correct output
`NO` view save

user output
`NO` view save

Test 3

Verdict: WRONG ANSWER

input
`10 10 ...#..A.#. ....B...## ...#...... .......... ...` view save

correct output
`YES 3 LLD` view save

user output
`YES 5 RDLLL` view save

Test 4

Verdict: ACCEPTED

input
`10 10 .#........ .......... .......... ........#. ...` view save

correct output
`YES 1 R` view save

user output
`YES 1 R` view save

Test 5

Verdict: WRONG ANSWER

input
`10 10 .......... .......... .......... .......... ...` view save

correct output
`YES 3 RDD` view save

user output
`YES 21 RRRRRRDLLLLLLLLLDRRRR` view save

Test 6

Verdict: ACCEPTED

input
`1000 1000 ##.###..######.#########.###.#...` view save

correct output
`NO` view save

user output
`NO` view save

Test 7

Verdict: RUNTIME ERROR

input
`1000 1000 ####.#.###....#.......##.##.#....` view save

correct output
`YES 626 LLLDDRDDDDLDLDDLLLLLDDDDLLDLDL...` view save

user output
(empty)

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 63, in <module>
    out = dfs(si, sj)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 54, in dfs
    s = dfs(i+1, j)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  [Previous line repeated 1 more time]
  File "/box/input/code.py", line 56, in dfs
    s = dfs(i-1, j)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 56, in dfs
    s = dfs(i-1, j)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 56, in dfs
    s = dfs(i-1, j)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/...

Test 8

Verdict: RUNTIME ERROR

input
`1000 1000 ....#.##......#....#......#......` view save

correct output
`YES 364 LULULLULLLULLLLLUULLLLUUULLLLL...` view save

user output
(empty)

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 63, in <module>
    out = dfs(si, sj)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  [Previous line repeated 6 more times]
  File "/box/input/code.py", line 56, in dfs
    s = dfs(i-1, j)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 56, in dfs
    s = dfs(i-1, j)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 56, in dfs
    s = dfs(i-1, j)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "...

Test 9

Verdict: RUNTIME ERROR

input
`1000 1000 .................#......#........` view save

correct output
`YES 1003 LLLLLLLLLLLLLLLLLLLLLLLLLDLLLL...` view save

user output
(empty)

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 63, in <module>
    out = dfs(si, sj)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  [Previous line repeated 22 more times]
  File "/box/input/code.py", line 54, in dfs
    s = dfs(i+1, j)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 54, in dfs
    s = dfs(i+1, j)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  [Previous line repeated 10 more times]
  File "/box/input/code.py", line 54, in dfs
    s = dfs(i+1, j)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", li...

Test 10

Verdict: RUNTIME ERROR

input
`1000 1000 .................................` view save

correct output
`YES 947 LLLLLLLLLLLLLLLLLLLLLLLLLLLLLL...` view save

user output
(empty)

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 63, in <module>
    out = dfs(si, sj)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  [Previous line repeated 551 more times]
  File "/box/input/code.py", line 54, in dfs
    s = dfs(i+1, j)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  [Previous line repeated 996 more times]
  File "/box/input/code.py", line 54, in dfs
    s = dfs(i+1, j)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  [Previous line repeated 6 more times]
  File "/box/input/code.py", line 38, in dfs
    visit...

Test 11

Verdict: RUNTIME ERROR

input
`1000 3 A#B .#. .#. .#. ...` view save

correct output
`YES 2000 DDDDDDDDDDDDDDDDDDDDDDDDDDDDDD...` view save

user output
(empty)

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 18, in <module>
    map[i] = line
IndexError: list index out of range

Test 12

Verdict: RUNTIME ERROR

input
`3 1000 A................................` view save

correct output
`YES 2000 RRRRRRRRRRRRRRRRRRRRRRRRRRRRRR...` view save

user output
(empty)

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 63, in <module>
    out = dfs(si, sj)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  [Previous line repeated 996 more times]
  File "/box/input/code.py", line 54, in dfs
    s = dfs(i+1, j)
  File "/box/input/code.py", line 54, in dfs
    s = dfs(i+1, j)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  [Previous line repeated 607 more times]
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 36, in dfs
    if (i,j) in visited:
RecursionError: maximum recursion depth exceeded

Test 13

Verdict: RUNTIME ERROR

input
`999 999 A#...#...#...#...#...#...#...#...` view save

correct output
`YES 499998 DDDDDDDDDDDDDDDDDDDDDDDDDDDDDD...` view save

user output
(empty)

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 63, in <module>
    out = dfs(si, sj)
  File "/box/input/code.py", line 54, in dfs
    s = dfs(i+1, j)
  File "/box/input/code.py", line 54, in dfs
    s = dfs(i+1, j)
  File "/box/input/code.py", line 54, in dfs
    s = dfs(i+1, j)
  [Previous line repeated 995 more times]
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 56, in dfs
    s = dfs(i-1, j)
  File "/box/input/code.py", line 56, in dfs
    s = dfs(i-1, j)
  File "/box/input/code.py", line 56, in dfs
    s = dfs(i-1, j)
  [Previous line repeated 438 more times]
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 36, in dfs
    if (i,j) in visited:
RecursionError: maximum recursion depth exceeded

Test 14

Verdict: ACCEPTED

input
`1 3 A.B` view save

correct output
`YES 2 RR` view save

user output
`YES 2 RR` view save

Test 15

Verdict: ACCEPTED

input
`2 2 ## AB` view save

correct output
`YES 1 R` view save

user output
`YES 1 R` view save

Test 16

Verdict: RUNTIME ERROR

input
`1000 1000 A................................` view save

correct output
`YES 1998 RRRRRRRRRRRRRRRRRRRRRRRRRRRRRR...` view save

user output
(empty)

Error:

Traceback (most recent call last):
  File "/box/input/code.py", line 63, in <module>
    out = dfs(si, sj)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  [Previous line repeated 996 more times]
  File "/box/input/code.py", line 54, in dfs
    s = dfs(i+1, j)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  File "/box/input/code.py", line 52, in dfs
    s = dfs(i, j-1)
  [Previous line repeated 689 more times]
  File "/box/input/code.py", line 50, in dfs
    s = dfs(i, j+1)
  File "/box/input/code.py", line 36, in dfs
    if (i,j) in visited:
RecursionError: maximum recursion depth exceeded

Aalto Competitive Programming 2026 - wk2 - Mon

Abandoned warehouse

Code

Test details

Test 1

Test 2

Test 3

Test 4

Test 5

Test 6

Test 7

Test 8

Test 9

Test 10

Test 11

Test 12

Test 13

Test 14

Test 15

Test 16

Tasks

Submissions (aalto26bm_010)