查找长度大到10,000的字符串的子序列

def find_subsequence(s: str, n: int) -> str:
    dp = [[0] * (n + 1) for _ in range(n + 1)]
    for i in range(1, n + 1):
        for j in range(i + 1, n + 1):
            if s[i - 1] == s[j - 1] and dp[i - 1][j - 1] + 1 > dp[i][j]:
                dp[i][j] = dp[i - 1][j - 1] + 1
            elif dp[i - 1][j] > dp[i][j - 1]:
                dp[i][j] = dp[i - 1][j]
            else:
                dp[i][j] = dp[i][j - 1]
    return dp[n][n]

s = "这里是一个长度大于10,000的字符串"
n = 10000
result = find_subsequence(s, n)
print(result)