Lec10-Tree Recursion

2024-10-14 98 words One minute

Contents

Tree Recursion

Inverse Cascade

Tree Recursion

计算斐波那契数列

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def fib(n):
    if n == 0:
        return 0
    elif n == 1:
        return 1
    else:
        return fib(n-1) + fib(n-2)

并不是最好的实现 -> 在遍历的时候会重复计算相同的节点，得想办法存储中间结果 🤔

Counting Partitions

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def count_partitions(n, m):
    """
    >>> count_partitions(6, 4)
    9
    """
    if n == 0:
        return 1
    elif n < 0 or m < 0:
        return 0
    elif m == 0:
        return 0
    else:
        with_m = count_partitions(n-m, m)
        without_m = count_partitions(n, m-1)
        return with_m + without_m