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Zollex
Asked:2021-12-04 21:58:43 +0000 UTC2021-12-04 21:58:43 +0000 UTC

是否可以加快这个 Python 代码的速度？

  • 772
def is_sorted(sequence) -> bool: 
    it = iter(sequence) 
    try: 
        lhs = next(it) 
    except StopIteration:
        raise ValueError('Empty sequence')
    for rhs in it:  
        if lhs <= rhs:
            lhs = rhs
        else:
            return False
    return True  
arr = []
s = []
a, q = map(int, input().split())
for i in range(a, q + 1):
    c = []
    k = str(i)
    for h in range(0, len(str(i))):
        d = k[h]
        c.append(d)
    s.append(c)
for j in range(0, len(s)):
    f = []
    for v in range(0, len(s[j])):
        g = s[j]
        g1 = g[v]
        gi = int(g1)
        f.append(gi)
    arr.append(f)
ls = list(filter(is_sorted, arr))
print(len(ls))

代码运行时间过长。可以加速吗？如果是这样，怎么做？不使用第三方模块

python

1 个回答

  1. Best Answer

    首先，让我们删除明显的垃圾：

    def is_sorted(sequence) -> bool: 
    it = iter(sequence) 
    try: 
        lhs = next(it) 
    except StopIteration:
        raise ValueError('Empty sequence')
    for rhs in it:  
        if lhs <= rhs:
            lhs = rhs
        else:
            return False
    return True  

a, q = map(int, input().split())

s = [list(str(i)) for i in range(a, q + 1)]

arr = [[int(digit) for digit in obj] for obj in s]

ls = list(filter(is_sorted, arr))

print(len(ls))

    很明显，程序是按数字升序计算数字a的q个数

    这段代码会更好：

    a, q = map(int, input().split())

count = 0
for num in range(a, q + 1):
    if str(num) == ''.join(sorted(str(num))):
        count += 1

print(count)

    这段代码更短：

    a, q = map(int, input().split())

print(len([num for num in range(a, q + 1) if str(num) == ''.join(sorted(str(num)))]))

    或者像这样：

    print(len([num for num in range(a, q + 1) if num == int(''.join(sorted(str(num))))]))

    但这几乎是最快的代码，因为没有不必要的转换

    count = 0

for num in range(a, q + 1):
    is_sorted = True
    old_digit = 10
    while num != 0:
        if num % 10 > old_digit:
            is_sorted = False
            break
        old_digit = num % 10
        num //= 10
    count += is_sorted

print(count)
    • 2

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