#!/usr/bin/env python# -*- coding: <encoding name> -*- '''全排列的demoinput : 3output:123 132 213 231 312 321''' total = 0 def permutationCove(startIndex, n, numList):  '''遞歸實(shí)現(xiàn)交換其中的兩個(gè)。一直循環(huán)下去，直至startIndex == n  '''  global total  if startIndex >= n:    total += 1    print numList    return      for item in range(startIndex, n):    numList[startIndex], numList[item] = numList[item], numList[startIndex]    permutationCove(startIndex + 1, n, numList )    numList[startIndex], numList[item] = numList[item], numList[startIndex]       n = int(raw_input("please input your number:"))startIndex = 0total = 0numList = [x for x in range(1,n+1)]print '*' * 20for item in range(0, n):  numList[startIndex], numList[item] = numList[item], numList[startIndex]  permutationCove(startIndex + 1, n, numList)  numList[startIndex], numList[item] = numList[item], numList[startIndex] print total