【算法编程 C++ Python】字符串替换

#include <iostream>
using namespace std;
class Solution {
public:
void replaceSpace(char * str, int length) {
// 在str原地址上替换，先遍历空格数量，再从后向前替换（从前向后替换费时费力）
int n = strlen(str);// 原字符串长度，不包含\0
int space_num = ;
for (int i = ; i < n; i++) {
if (str[i] == ' ') {
space_num++;
}
}
int n_new = n + space_num*; //一个空格变成三个字符%20
while ((n>=)&&(n_new>n))
{
cout << str[n] << endl;
// 从'\0'开始
if (str[n] == ' ') {
str[n_new--] = '';
str[n_new--] = '';
str[n_new--] = '%';
}
else { str[n_new--] = str[n];
}
n--;
}
}
};int main()
{
Solution obj;
char* str = "hello world";
int n = strlen(str);// 字符串长度，不包含\0
obj.replaceSpace(str, n);
cout << str << endl;
cin.get();
cin.get();
return ;
}

# -*- coding:utf-8 -*-
class Solution:
def replaceSpace(self, s):
s_new = ""
n = len(s)
for i in xrange(n):
if s[i]==' ':
s_new += "%20"
else:
s_new += s[i]
return s_newif __name__ == '__main__':
obj = Solution()
s = "hello world"
print obj.replaceSpace(s)