/*

*

* The API: int read4(char *buf) reads 4 characters at a time from a file.

The return value is the actual number of characters read. For example,

it returns 3 if there is only 3 characters left in the file.

By using the read4 API, implement the function int read(char *buf, int n)

that reads n characters from the file.

Note:

The read function will only be called once for each test case.

*/

package leetcode;

import java.util.*;

public class ReadNCharacter {

char a = 'a';

public int read(char[] buf, int n){

int counter = 0;

while(counter < n){

char[] temp = new char[4];

int r = read4(temp);

for(int i=0;i<r && counter<n;i++){

buf[counter] = temp[i];

counter++;

}

if(r<4)

break;

}

return counter;

}

private int read4(char[] buf){

for(int i=0;i<4;i++){

buf[i] = this.a++;

}

return 4;

}

public static void main(String[] args) {

ReadNCharacter rc = new ReadNCharacter();

int n = 5;

char[] buf = new char[n];

rc.read(buf, n);

System.out.println(buf);

}

}