python 实现：题目：有n个人围成一圈，顺序排号。从第一个人开始报数（从1到3报数），凡报到3的人退出圈子，问最后留下的是原来第几号的那位。

自己写的，是利用列表仿照报数过程一个一个把人踢出去最后得到结果：

count = int(raw_input('Please input the count:'))
li = []
for i in range(count):
    li.append(i+1)
times = count/3 +2
count_tial = 0
for i in range(times):
    for j in range(count_tial+1,len(li)+count_tial+1):
        if count_tial == 2:
            li[0] = 0
        if (j - count_tial) < len(li) and (j+1)%3 == 0:
            li[j - count_tial] = 0
    count_0 = li.count(0)
    try:
        count_tial = len(li) - li.index(0,len(li)-3,len(li))-1
    except Exception,e:
        break
    for i in range(len(li)):
        try:
            li.remove(0)
        except:pass
if len(li) == 2:
    print '\n   ! ! ! The last is:',li[1],' ! ! !'
else:print '\n   ! ! ! The last is:',li[0],' ! ! !'
print '\n(last li:',li,')'

下面代码打印出了踢人的过程：

count = int(raw_input('Please input the count:'))
li = []
for i in range(count):
    li.append(i+1)
print li
times = count/3 +2
count_tial = 0
for i in range(times):
    for j in range(count_tial+1,len(li)+count_tial+1):
        if count_tial == 2:
            li[0] = 0
        if (j - count_tial) < len(li) and (j+1)%3 == 0:
            li[j - count_tial] = 0
    print 'set 0 li:',li
    count_0 = li.count(0)
    print 'count_0:',count_0
    try:
        print 'index of last 0:',li.index(0,len(li)-3,len(li))
        count_tial = len(li) - li.index(0,len(li)-3,len(li))-1
    except Exception,e:
        break
    print 'count_tial:',count_tial
    for i in range(len(li)):
        try:
            li.remove(0)
        except:pass
    print 'after remove 0 :',li
if len(li) == 2:
    print '\n\n   ! ! ! The last is:',li[1],' ! ! !'
else:print '\n\n   ! ! ! The last is:',li[0],' ! ! !'
print '\n(last li:',li,')'