Nested loop used in hcf finding code in Python returns IndexError:index out of range

Question

我创建了一个程序，可以生成给定两个数字的 HCF（最大公因数）。

f1 = []
f2 = []
num1 = int(input("Enter first number:"))
num2 = int(input("Enter second number:"))
n1 = num1 + 1
n2 = num2 + 1
for i in range(1,n1):
      if num1%i == 0: f1.append(i)
for j in range(1,n2):
      if num2%j == 0: f2.append(j)
hcf = 1
for x in range(0,(len(f1)+1) ):
    for y in range(0,(len(f2)+1)):
        if f1[x]==f2[y]:
            hcf = f2[y]
print("The highest common factor of "+str(num1)+" and "+str(num2)+" is "+str(hcf))

在找到两个数字的因数之前，它工作正常。但是当程序是运行时，它在if f1[x]==f2[y]:处显示索引错误。错误是：

    if f1[x]==f2[y]:
IndexError: list index out of range

出现此错误的原因是什么，我该如何纠正？

Answer 1

for x in range(0,(len(f1)+1) ):
   for y in range(0,(len(f2)+1)):
    if f1[x]==f2[y]:
        hcf = f2[y]

问题是 range(0, len(f1)+1) 从 0 到列表的长度 + 1，我想你不会有这个问题，如果你将其替换为：

for x in f1:
  for y in f2:
    if x == y:
     hcf = y

Answer 2

不需要len(f1)+1。以下应该有效。

f1 = []
f2 = []
num1 = int(input("Enter first number:"))
num2 = int(input("Enter second number:"))
n1 = num1 + 1
n2 = num2 + 1
for i in range(1,n1):
    if num1%i == 0: f1.append(i)
for j in range(1,n2):
    if num2%j == 0: f2.append(j)
hcf = 1
for x in range(0,(len(f1)) ):
    for y in range(0,(len(f2))):
        print "{0} : {1}".format(x, y)
        if f1[x]==f2[y]:
            hcf = f2[y]
print("The highest common factor of "+str(num1)+" and "+str(num2)+" is "+str(hcf))

Nested loop used in hcf finding code in Python returns IndexError:index out of range

Nested loop used in hcf finding code in Python returns IndexError:index out of range

python

python-3.x

index-error