/*
 * Fall09 Midterm 1 Programming Exam 
 * 
 * draw a histogram of student midterm grades
 * 
 * Dependencies: StdIn, StdDraw
 * */

public class Histogram {
  public static void main(String[] args) {
    
    int BARS = 21;
    int[] hist = new int[BARS];
    int RANGE = 100/(BARS - 1);

    
    // read in data - We don't know how many students
    int studNum = 0;
    while (!StdIn.isEmpty()) {
      String name = StdIn.readString();
      studNum++;
      double midterm = StdIn.readDouble();
      
      // save info for bar graph (histogram)
      int index = (int) (midterm / RANGE);
      hist[index] = hist[index] + 1;
    }
    
    // draw histogram
    StdDraw.setPenRadius(.025);
    StdDraw.setXscale(0, BARS);
    StdDraw.setYscale(0, studNum); 
    for (int i = 0; i < BARS; i++) {
      StdDraw.line(i, 0, i, hist[i]);
    }
  }
}