題目描述:請實現一個函數,把字符串 s 中的每個空格替換成"%20"
示例 1:
輸入:s = “We are happy.”
輸出:“We%20are%20happy.”
限制:
0 <= s 的長度 <= 10000
解題思路:雙指針遍歷替換法
class Solution {
public:
string replaceSpace(string s) {
int count = 0;
int len = s.size();
for(char c : s)
{
if( c==' ')
count++;
}
s.resize(len+count*2);
for(int i = len-1,j = s.size()-1;i < j;i--,j--)
{
if(s[i] != ' ')
{
s[j] = s[i];
}
else
{
s[j-2] = '%';
s[j-1] = '2';
s[j] = '0';
j -= 2;
}
}
return s;
}
};