问题描述
暴力法:
package cn.jnu.ma02;
public class Solution {
public static void main(String[] args) {
String s="we are happy";
StringBuffer str = new StringBuffer(s);
System.out.println(s);
System.out.println(replaceSpace(str));
}
public static String replaceSpace(StringBuffer str) {
if (str == null || str.length() == 0) {
return str.toString();
}
StringBuilder sb = new StringBuilder();
int len = str.length();
for (int i = 0; i < len; ++i) {
char ch = str.charAt(i);
sb.append(ch == ' ' ? "%20" : ch);
}
return sb.toString();
}
}
思路二:双指针法
package cn.jnu.ma02;
public class Solution2 {
public static void main(String[] args) {
String s="we are happy";
StringBuffer str = new StringBuffer(s);
System.out.println(s);
System.out.println(replaceSpace(str));
}
public static String replaceSpace(StringBuffer str){
if (str == null || str.length() == 0) {
return str.toString();
}
int len = str.length();
for (int i = 0; i < len; ++i) {
if (str.charAt(i) == ' ') {
str.append(" ");
}
}
int p = len - 1;
int q = str.length() - 1;
while (p >= 0) {
char ch = str.charAt(p--);
if (ch == ' ') {
str.setCharAt(q--, '0');
str.setCharAt(q--, '2');
str.setCharAt(q--, '%');
} else {
str.setCharAt(q--, ch);
}
}
return str.toString();
}
}