OJ按字节截取字符串

import java.util.Scanner;

public class Main {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

String str1 = sc.next();

int num =sc.nextInt();

sc.close();

char ch[] = str1.toCharArray();

for (int i = 0; i < ch.length;i++) {

if(ch[i] < 255){

num = num -1;

}else{

num = num -2;

}

if(num <= 1){

if(ch[i]>255){

break;

}

if(num<0)break;

}

System.out.print(ch[i]);

}

}

}