Buggy python submission (verdict: Runtime Error):
import sys
n = int(input())
mem = [None]*(n+1)
def DFS(k, d):
    if k<0 or d>2000:
        return 10**9
    if k==0:
        return 0
    if k<6:
        return k
    if mem[k] is not None:
        return mem[k]
    tmp = 10**5
    for i in range(1, 7):
        tmp = min(tmp, DFS(k-6**i, d+1)+1)
    for i in range(1, 6):
        tmp = min(tmp, DFS(k-9**i, d+1)+1)
    mem[k] = tmp
    return tmp
if n<6:
    print(n)
else:
    print(DFS(n, 0))

Fixed submission:
import sys
n = int(input())
INF = 10*n
dp = [INF]*(n+1)
dp[0] = 0
for i in range(1, n+1):
    tmp = dp[i-1] + 1
    for j in range(10):
        if i-6**j<0:
            break
        tmp = min(tmp, dp[i-6**j] + 1)
    for j in range(10):
        if i-9**j<0:
            break
        tmp = min(tmp, dp[i-9**j] + 1)
    dp[i] = tmp
print(dp[n])

Buggy python submission (verdict: Runtime Error):
import sys
n = int(input())
mem = [None]*(n+1)
def DFS(k, d):
    if k<0 or d>5000:
        return 10**9
    if k==0:
        return 0
    if k<6:
        return k
    if mem[k] is not None:
        return mem[k]
    tmp = 10**5
    for i in range(1, 7):
        tmp = min(tmp, DFS(k-6**i, d+1)+1)
    for i in range(1, 6):
        tmp = min(tmp, DFS(k-9**i, d+1)+1)
    mem[k] = tmp
    return tmp
if n<6:
    print(n)
else:
    print(DFS(n, 0))

Fixed submission:
import sys
n = int(input())
INF = 10*n
dp = [INF]*(n+1)
dp[0] = 0
for i in range(1, n+1):
    tmp = dp[i-1] + 1
    for j in range(10):
        if i-6**j<0:
            break
        tmp = min(tmp, dp[i-6**j] + 1)
    for j in range(10):
        if i-9**j<0:
            break
        tmp = min(tmp, dp[i-9**j] + 1)
    dp[i] = tmp
print(dp[n])

Buggy python submission (verdict: Time Limit Exceeded):
import sys
n = int(input())
def DFS(n, t):
    tmp = 10**5
    if t<=5:
        for i in range(9):
            nxt = n-i*(9**(6-t))
            if nxt<0:
                continue
            tmp = min(tmp, DFS(nxt, t+1)+i)
        return tmp
    elif t<=11:
        for i in range(6):
            nxt = n-i*(6**(12-t))
            if nxt<0:
                continue
            tmp = min(tmp, DFS(nxt, t+1)+i)
        return tmp
    else:
        if n<6:
            return n
        else:
            return 10**5
print(DFS(n, 1))

Fixed submission:
import sys
n = int(input())
INF = 10*n
dp = [INF]*(n+1)
dp[0] = 0
for i in range(1, n+1):
    tmp = dp[i-1] + 1
    for j in range(10):
        if i-6**j<0:
            break
        tmp = min(tmp, dp[i-6**j] + 1)
    for j in range(10):
        if i-9**j<0:
            break
        tmp = min(tmp, dp[i-9**j] + 1)
    dp[i] = tmp
print(dp[n])

Buggy python submission (verdict: Time Limit Exceeded):
from collections import deque
n = int(input())
q = deque([(0, 0, 0)])
while q:
    now, cnt, stat = q.popleft()
    if now>n:
        continue
    if now==n:
        print(cnt)
        break
    for i in range(1, 8):
        if stat<=i:
            q.append((now+6**i, cnt+1, i))
    for i in range(1, 7):
        if stat<=i+7:
            q.append((now+9**i, cnt+1, i+7))
    q.append((now+1, cnt+1, 14))

Fixed submission:
import sys
n = int(input())
INF = 10*n
dp = [INF]*(n+1)
dp[0] = 0
for i in range(1, n+1):
    tmp = dp[i-1] + 1
    for j in range(10):
        if i-6**j<0:
            break
        tmp = min(tmp, dp[i-6**j] + 1)
    for j in range(10):
        if i-9**j<0:
            break
        tmp = min(tmp, dp[i-9**j] + 1)
    dp[i] = tmp
print(dp[n])