字符串反转

标签：java   string   字符串   反转   

java实现的字符串翻转，能想到的这几种方法

如果有其他方法，欢迎交流

//字符串反转
public class ReverseString {
	public String reverse1(String str){
		StringBuffer sb = new StringBuffer(str);
		str = sb.reverse().toString();
		return str;
	}
	
	public String reverse2(String str){
		char[] ch = str.toCharArray();
		StringBuffer sb = new StringBuffer();
		for(int i=ch.length;i>0;i--){
			sb.append(ch[i-1]);
		}
		return sb.toString();
	}
	
	public String reverse3(String str){
		StringBuffer sb = new StringBuffer();
		for(int i=str.length()-1;i>=0;i--){
			sb.append(str.charAt(i));
		}
		return sb.toString();
	}
	
	//O(logn)
	public String reverse4(String str){
		char[] a = str.toCharArray();
		for(int i=0;i<str.length()/2;i++){
			char temp = a[i];
			a[i] = a[a.length-i-1];
			a[a.length-i-1] = temp;
		}
		return String.valueOf(a);
	}
	
	public String reverse5(String str,int start,int end){
		int i=start;
		int j=end;
		char[] a = str.toCharArray();
		while(i<j){
			char temp = a[i];
			a[i] = a[j];
			a[j] = temp;
			i++;
			j--;
		}
		return String.valueOf(a);
	}
	
	public static void main(String[] arg){
		ReverseString rs = new ReverseString();
		String str = "a213aa d43d ddfs";
		String s = rs.reverse1(str);
		System.out.println("reverse1:"+s);
		s = rs.reverse2(str);
		System.out.println("reverse2:"+s);
		s = rs.reverse3(str);
		System.out.println("reverse3:"+s);
		s = rs.reverse4(str);
		System.out.println("reverse4:"+s);
		s = rs.reverse5(str,0,str.length()-1);
		System.out.println("reverse5:"+s);
	}
}

转载请注明：http://blog.csdn.net/df1012890048  

字符串反转

标签：java   string   字符串   反转   

原文地址：http://blog.csdn.net/df1012890048/article/details/38168679