ReadNCharacters.java

package array;

/**
 * Created by gouthamvidyapradhan on 09/12/2017.
 * 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.


 */
public class ReadNCharacters {

    /**
     * Main method
     * @param args
     */
    public static void main(String[] args) {

    }

    /**
     *
     * @param buf
     * @param n
     * @return
     */
    public int read(char[] buf, int n) {
        int i = 0;
        int toRead = Math.min(n, buf.length);
        while(i < toRead){
            char[] temp = new char[4];
            int r = read4(temp);
            for(int j = 0; j < r && i < toRead; j ++){
                buf[i] = temp[j];
                i++;
            }
            if(r < 4) break;
        }
        return Math.min(i, toRead);
    }


    private int read4(char[] buf){
        return 1;//return fake value just to resolve compilation error
    }

}