For 循环编程题

Q：

Assume s is a string of lower case characters.

Write a program that prints the longest substring of s in which the letters occur in alphabetical order. For example, if s = 'azcbobobegghakl', then your program should print

Longest substring in alphabetical order is: beggh


A：
curString = s[0]
longest = s[0]
for i in range(1, len(s)):
    if s[i] >= curString[-1]:
        curString += s[i]
        if len(curString) > len(longest):
            longest = curString
    else:
        curString = s[i]
print 'Longest substring in alphabetical order is:', longest
思路整理：
初始化: 连续的字符串为s[0]; 最长的连续字符串是s[0]
如果s中的字符大于或等于连续字符串中的最后一个字符，则累加，并改变最长字符串的值；
否则重新设置连续字符串的首字符为s[i]