Please help me with my java code

help
,
1

i was doing this question : FLIPSORT Problem - CodeChef

i submitted my code in JAVA : CodeChef: Practical coding for everyone
which is giving error but the same code is accepted in cpp : CodeChef: Practical coding for everyone

can anybody please help me and tell why my java code is producing error.

2

Hey @akashagarwal00 :wave: ,
Your java code is failing due to Reader class change that to Scanner and it passes fine.
I have modified your java code and it worked.

import java.util.*;
import java.lang.*;
import java.io.*;
class Codechef
{
    static class Reader {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;
 
        public Reader()
        {
            din = new DataInputStream(System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }
 
        public Reader(String file_name) throws IOException
        {
            din = new DataInputStream(
                new FileInputStream(file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }
 
        public String readLine() throws IOException
        {
            byte[] buf = new byte[64]; // line length
            int cnt = 0, c;
            while ((c = read()) != -1) {
                if (c == '\n') {
                    if (cnt != 0) {
                        break;
                    }
                    else {
                        continue;
                    }
                }
                buf[cnt++] = (byte)c;
            }
            return new String(buf, 0, cnt);
        }
 
        public int nextInt() throws IOException
        {
            int ret = 0;
            byte c = read();
            while (c <= ' ') {
                c = read();
            }
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
 
            if (neg)
                return -ret;
            return ret;
        }
 
        public long nextLong() throws IOException
        {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }
 
        public double nextDouble() throws IOException
        {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
 
            do {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
 
            if (c == '.') {
                while ((c = read()) >= '0' && c <= '9') {
                    ret += (c - '0') / (div *= 10);
                }
            }
 
            if (neg)
                return -ret;
            return ret;
        }
 
        private void fillBuffer() throws IOException
        {
            bytesRead = din.read(buffer, bufferPointer = 0,
                                 BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }
 
        private byte read() throws IOException
        {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }
 
        public void close() throws IOException
        {
            if (din == null)
                return;
            din.close();
        }
    }
 
	public static void main (String[] args) throws java.lang.Exception
	{
    	Scanner sc = new Scanner(System.in);
    	final int mod = 1000000007;
        int t = sc.nextInt();
        while(t-- > 0){
          int n = sc.nextInt();
          String s = sc.next();
          char target = '1';
          Map<Integer, Integer> mp = new LinkedHashMap<>();
          
          for(int i=0;i<n;i++) {
              if(s.charAt(i) == target) {
                  mp.put(i+1, n-i);
                  
                  if(target == '1') {
                      target = '0';
                  }
                  else {
                      target = '1';
                  }
              }
          }
          
          System.out.println(mp.size());
          for(Map.Entry it : mp.entrySet()) {
              System.out.println(it.getKey() + " " + it.getValue());
          }
          
        }
	}
}
1 Like
3

Does that means that i can not use reader class to take binary strings as input.
Also i saw it in gfg to use this for faster input and output should i continue using it or not?