卡普雷卡数

Question

def kaprekar_num(num):
    count = 0
    while count <= num:
        n = 1
        sqr = n ** 2
        digits = str(sqr)
        length = len(digits)
        for x in range(1, length):
            left = int("".join(digits[:x]))
            right = int("".join(digits[x:]))
            if (left + right) == n:
                print("Number: " + str(n) + ", Left: " + str(left) + " + " + " Right: " + str(right) + " = " + str(n))
                n += 1
                count += 1
            else:
                n += 1
kaprekar_num(5)

大家好， 我是python编程新手，课堂上有一项任务，就是打印前5个kaprekar数。 （我只有C编程背景…） 我对“范围内的x…”行有问题。。代码没有进入循环，我不知道为什么。 该程序需要打印：

Number: 9, Left: 8 +  Right: 1 = 9
Number: 10, Left: 10 +  Right: 0 = 10
Number: 45, Left: 20 +  Right: 25 = 45
Number: 55, Left: 30 +  Right: 25 = 55
Number: 99, Left: 98 +  Right: 1 = 99

我将感谢一些见解：）

Answer 1

您如何管理n值是不正确的。它应该在循环开始之前设置，然后在每次尝试之后，不管结果如何，它都应该递增

def kaprekar_num(num):
    count = 0
    # Start n at one, and don't reset it on each loop
    n = 1
    while count <= num:
        sqr = n ** 2
        digits = str(sqr)
        length = len(digits)
        for x in range(1, length):
            left = int("".join(digits[:x]))
            right = int("".join(digits[x:]))
            if (left + right) == n:
                print("Number: " + str(n) + ", Left: " + str(left) + " + " + " Right: " + str(right) + " = " + str(n))
                count += 1
                # This number is a Kaprekar number, so break out of the loop
                break
        # Regardless of the status of this number, try the next one
        n += 1
kaprekar_num(5)

作为一项建议：我强烈建议您将来使用调试器逐步完成代码。如果你这么做了，你会发现n的变化并不是很快

Answer 2

for循环很好，有一些逻辑问题，您还没有处理，比如当n==1和len（sqr）==1时

def kaprekar_num(num):
    count = 0
    n=1
    while count <= num:
         

        sqr = n ** 2
        digits = str(sqr)
        length = len(digits)
        if sqr==1:
            print("Number: " + str(n)  + " = " + str(n))
            count+=1
            n+=1
        elif length>1:
            for x in range(1,length):
                left = int("".join(digits[:x]))
                right = int("".join(digits[x:]))
                if (left + right) == n:
                    print("Number: " + str(n) + ", Left: " + str(left) + " + " + " Right: " + str(right) + " = " + str(n))
                    n += 1
                    count += 1
                else:
                    n += 1
        else:
            n+=1
            
kaprekar_num(5)

Answer 3

你把循环设置为重复一次，我想，如果你想把n代替1，我想这就是问题所在

尝试将循环设置为该值

for x in range(n, length):