Question

python 题目

给定一个由不同整数a1,a2,…,an按升序排列而成的序列，利用二分搜索确定是否存在某个下标i使得ai=i

Answer 1

#-*- coding:utf-8 -*-
def binary_search(slist,goal):
'''二分查找 slist为要查找的列表，goal为目标

Return middle为目标的下标'''
low=0
high=len(slist)-1
while(low<=high):
middle=(high-low)/2+low
if(slist[middle]==goal):
return middle
elif(slist[middle]>goal):
high=middle-1
elif(slist[middle]<goal):
low=middle+1
return -1

Answer 2

#!/usr/bin/env python#-*- coding:utf-8 -*-def sum_digits(number): """Return the sum of the number's digits""" remain = number sumn = 0 while remain>0: sumn += remain % 10 remain = remain // 10 return sumndef main(): """To interact with user""" while True : numberstr = raw_input("Enter a number:") if numberstr.isdigit(): result = sum_digits(int(numberstr)) print "Sum of digits: {0}".format(result) break else: print "An int type you entered is not valid!"if __name__ == '__main__': main()
以上回答你满意么？