用python的while循环来编写2、3、4、5个数字,能组成多少个互不相同且无重复数的三位数，以逗号隔开，并另起一行输出个数，如：
234,235,243,245,253,254,324,325,342,345,352,354,423,425,432,435,452,453,523,524,532,534,542,543,
24
解答：
n=0
x=1
while x<=4:
x+=1
y=1
while y<=4:
y+=1
z=1
while z<=4:
z+=1
if (x!=y) and (y!=z) and (z!=x):
print(x,end="")
print(y,end="")
print(z,end=",")
n+=1
print()
print(n)
【其中
print(x,end="")
print(y,end="")
print(z,end=",")
可改为
print("%d%d%d" % (x, y, z),end=",")
或
print(str(x)+str(y)+str(z),end=",")
】
其实本题用for循环来编写更容易
n=0
for x in range(2,6):
for y in range(2,6):
for z in range(2,6):
if (x!=y) and (y!=z) and (z!=x):
print("%d%d%d" % (x, y, z),end=",")
n+=1
print()
print(n)