从插入代码中获取正确的输出匹配

问：

我无法让iter_position_reverse中的测试用例字符串通过。我不确定我必须更改什么才能解决这个问题

这是iterrative_insertion代码：

def iterrative_insertion(S, positions):
    R = S
    offset = 0
    for pos in positions:
        R = R[:pos + offset] + S + R[pos + offset:]
        offset + len(S)
    return R

# Example usage
S = "abcdabd"
positions = [0, 1, 16]
result = iterrative_insertion(S, positions)
expected = 'aabcdabdbcdabdababcdabdcdabd'
print(expected)
print(result)
print(result == expected)
print(len(result),len(S), len(expected))

# abcdabd
# abcdabdabcdabd
# aabcdabdbcdabdabcdabd
# aabcdabdbcdabdababcdabdcdabd

这是我拥有iter_position_reverse代码：

import iterrative_insertion
def iter_position_reverse(R):
    # Initialize variables to store S and positions
    S = ""
    positions = []

    # Start iterating through R
    i = 0
    while i < len(R):
        # Find the longest substring that matches the beginning of R
        j = 0
        while j < len(S) and i + j < len(R) and S[j] == R[i + j]:
            j += 1

        # If we found a match, add its position to the positions list
        if j == len(S):
            positions.append(i)

        # If we didn't find a match, add the next character to S
        S += R[i]

        # Move to the next character in R
        i += 1

    return S, positions

# Test cases
test_strings = [
    "abcdabdaabcdabdbcdabdabcdabd",
    "aabcdabdbcdabdabcdabdabcdabd",
    "aababababcdabdcdabdcabcdabddabdcdabdbcdabd",
    "aaaaaaababababcdabdcdabdcabcdabddabdcdabdbcdabdababababcdabdcdabdcabcdabddabdcdabdbcdabdababababcdabdcdabdcabcdabddabdcdabdbcdabdbabababcdabdcdabdcabcdabddabdcdabdbcdabdababababcdabdcdabdcabcdabddabdcdabdbcdabd",
    "ddodoremefasolasiremefasolasioremdoredoremefasolasimefasolasiefasolasi",
    "abdaabcdabdbcdabdb"
]



for R in test_strings:
    S, positions = iter_position_reverse(R)
    print("Input String:", R)
    print("S:", S)
    print("Positions:", positions)
    print()
    if iterrative_insertion.iterrative_insertion(S,positions) == R:
        print("We did it.")
else:
    print(f"It did not work for {R}")

代码输出没有给出答案，无论是“我们做到了”还是“它对 {R} 不起作用”。

该代码尝试查找和重新构造与输入字符串开头匹配的输入字符串的子字符串，并存储这些匹配项的位置。然后，它检查重建的字符串在由 iterrative_insertion 函数处理时是否可以生成原始输入字符串。主要目标是测试和验证在 iter_position_reverse 中实现的字符串匹配和重建算法。