剑指offer 4题 【字符串】替换空格

题目描述

public class TitleSpace {
public String replaceSpace(StringBuffer str) {
int count = 0;
for(int i=0;i<str.length();i++){
if(str.charAt(i) == ' ')
count++;
}
char[] ch = new char[str.length()+ count*2];

int index = ch.length-1;
for(int i=str.length()-1;i>=0;i--){
if(str.charAt(i) == ' '){
ch[index--] = '0';
ch[index--] = '2';
ch[index--] = '%';
}else{
ch[index--] = str.charAt(i);
}
}
String result = new String(ch);
return result;
}

public static void main(String[] args) {
StringBuffer str = new StringBuffer("We Are Happy");
System.out.println(new TitleSpace().replaceSpace(str));
}
}