Help me in solving WHITEWALL problem

help
,
1

My issue

I’m getting a runtime error with no details, I can’t find the bug.
Link: CodeChef: Practical coding for everyone

My code

def f(idx, i, j):

    if idx >= len(s):
        return 0

    ans = float("inf")
    for c in ["R", "G", "B"]:
        if c != i and c != j:
            v = f(idx + 1, j, c)
            v += 0 if c == s[idx] else 1
            ans = min(ans, v)

    return ans


for _ in range(int(input())):
    n = int(input())
    s = input()
    ans = f(0, -1, -1)
    print(ans)

Problem Link: White Wall Practice Coding Problem

2

This is the error in your code:

RecursionError: maximum recursion depth exceeded
3

Oh！Thanks…！
I’m new here, it looks like Codechef is not friendly to recursion search, it may be Accept on platform like Leetcode.