1.python方法：把字符创转为list，然后遇到空格就把空格换为 ，最后合成字符串
# -*- coding:utf-8 -*- class Solution: # s 源字符串 def replaceSpace(self, s): # write code here s = list(s) count=len(s) for i in range(0,count): if s[i]==' ': s[i]=' ' return ''.join(s)2.统计出空格个数，算出替换后字符串长度，从后向前一次插入
# -*- coding:utf-8 -*- class Solution: # s 源字符串 def replaceSpace(self, s): # write code here blank = 0 n = len(s)-1 if s == None or n <= 0: return for i in range(n): if s[i] == ' ': blank += 1 newn = n + blank*2 s1 = [0]*newn while n > 0 and newn > n: if s[n] == ' ': s1[newn] = '0' newn -= 1 s1[newn] = '2' newn -= 1 s1[newn] = '%' newn -= 1 else: s1[newn] = s[n] newn -= 1 n -= 1 s2 = ''.join(s1) return s2