对换反转法:如果字符串的个数是奇数,不需要关注中间那个字符,或者让它和自己交换
package com.hello.ds;
public class Reverse {
public static String reverse(String str,int start,int end) {
char[]array=str.toCharArray();
int mid=(end-start)/2+start;
for(int i=0;i<mid-start;i++) {
swap(array,start+i,end-i);
}
return String.valueOf(array);
}
private static void swap(char[]array,int left,int right) {
char temp=array[left];
array[left]=array[right];
array[right]= temp;
}
public static void main(String[] args) {
// TODO Auto-generated method stub
Reverse r=new Reverse();
System.out.println(r.reverse("abcdefg", 0, 6));
System.out.println(r.reverse("abcdefg", 2, 4));
}
}