// Source code example for "A Practical Introduction
// to Data Structures and Algorithm Analysis"
// by Clifford A. Shaffer, Prentice Hall, 1998.
// Copyright 1998 by Clifford A. Shaffer

import java.io.*;

// This program tests a bunch of various code fragements from
// Chapter 3, mainly for syntactic correctness.
class Ch3main {
	
  static void sort(int[] A, int x) {}

  static boolean EVEN(int x)
  { return (x % 1) == 0; }

  final static int n = 100;

  public static void main(String args[]) throws IOException {
	int i, j, k;
	int sum, sum1, sum2, sum3;
	int a;
	int b = 10;

    int[] A = new int[n];

    for (i=0; i<n; i++)
      A[i] = i;

/// c3p1.x
sum = 0;
for (i=1; i<=n; i++)
   for (j=1; j<=n; j++)
      sum++;

System.out.println("Test 1: For n = " + n +", sum is " + sum);
System.out.println("It should be n^2.");

/// c3p2.x
a = b;

System.out.println("Test 2: b is " + b +" and a is " + a);

/// c3p3.x
sum = 0;
for (i=1; i<=n; i++)
   sum += n;

System.out.println("Test 3: For n = " + n +", n^2 is " + sum);

/// c3p4.x
sum = 0;
for (j=1; j<=n; j++)     // First for loop
   for (i=1; i<=j; i++)  //   is a double loop
      sum++;
for (k=0; k<n; k++)      // Second for loop
   A[k] = k;

System.out.println("Test 4: For n = " + n +
				   ", the sum from 1 to n is " + sum);

/// c3p5.x
sum1 = 0;
for (i=1; i<=n; i++)     // First double loop
   for (j=1; j<=n; j++)  //   do n times
      sum1++;

sum2 = 0;
for (i=1; i<=n; i++)     // Second double loop
   for (j=1; j<=i; j++)  //   do i times
      sum2++;

System.out.println("Test 5: This should be n^2: " + sum1);
System.out.println("Again, the sum from 1 to n is " + sum2);

/// c3p6.x
sum1 = 0;
for (k=1; k<=n; k*=2)
   for (j=1; j<=n; j++)
      sum1++;

sum2 = 0;
for (k=1; k<=n; k*=2)
   for (j=1; j<=k; j++)
      sum2++;

System.out.println("Test 6: For " + n +
				   ", the sum of n taken log n times is: " + sum1);
System.out.println("For " + n + ", the sum of 2^j is: " + sum2);

  int c = 1;
  int d = 2;
  int e = 3;

/// c3p7.x
a = b + c;
d = a + e;
/// End c3p7.x

  a = d ;


/// c3p8.x
sum = 0;
for (i=0; i<3; i++)
   for (j=0; j<n; j++)
      sum++;
/// End c3p8.x

/// c3p9.x
sum=0;
for (i=0; i<n*n; i++)
   sum++;
/// End c3p9.x

/// c3p10.x
for (i=0; i<n; i++) {
  for (j=0; j<n; j++)
    A[i] = DSutil.random(n); // random takes constant time
  sort(A, n);                // sort takes n log n time
}
/// End c3p10.x

System.out.println("Finally, do part 11.");

  for (i=0; i<n; i++)
    A[i] = i;

/// c3p11.x
sum3 = 0;
for (i=0; i<n; i++)
  for (j=0; A[j]!=i; j++)
    sum3++;

System.out.println("Sum 3 should be about 1/2 n^2: " + sum3);

/// c3p12.x
sum = 0;
if (EVEN(n))
  for (i=0; i<n; i++)
    sum++;
else
  sum = sum + n;

System.out.println("Final sum should just be 100: " + sum);

  System.in.read();
}
}