Exercises 1, 2, 3, 5, 8

[mdziedzic]

Exercise 1

Code: (Objective-C)

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

	NSLog(@"  n  |   n^2");
	NSLog(@"-----|---------");
	
	for (int i = 1; i <= 10; i++)
		NSLog(@" %2i  |  %3i", i, i * i);
 	
	[pool drain];
    return 0;
}

   n  |   n^2
 -----|---------
   1  |    1
   2  |    4
   3  |    9
   4  |   16
   5  |   25
   6  |   36
   7  |   49
   8  |   64
   9  |   81
  10  |  100




Exercise 2

Code: (Objective-C)

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
	
	NSLog(@"  n | triangle #");
	NSLog(@"----|------------");
    
	for (int i = 5; i <= 50; i += 5)
		NSLog(@" %2i |   %4i", i, i * (i + 1) / 2);
	
	[pool drain];
    return 0;
}

   n | triangle #
 ----|------------
   5 |     15
  10 |     55
  15 |    120
  20 |    210
  25 |    325
  30 |    465
  35 |    630
  40 |    820
  45 |   1035
  50 |   1275




Exercise 3

Code: (Objective-C)

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

	int factorial;
	
	NSLog(@"  n |    n!");
	NSLog(@"----|---------");
	
	for (int i = 1; i <= 10; i++) {
		factorial = 1;
		
		for (int j = 1; j <= i; j++)
			factorial *= j;
		
		NSLog(@" %2i | %7i", i, factorial);
	}
    
	[pool drain];
    return 0;
}

   n |    n!
 ----|---------
   1 |       1
   2 |       2
   3 |       6
   4 |      24
   5 |     120
   6 |     720
   7 |    5040
   8 |   40320
   9 |  362880
  10 | 3628800




Exercise 5

Code: (Objective-C)

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
	
	int n, number, triangulerNumber, counter, numberToCompute;
	
	NSLog(@"Number of triangular numbers to compute?");
	scanf("%i", &numberToCompute);
	
	for (counter = 1; counter <= numberToCompute; counter++) {
		NSLog(@"What triangular number do you want?");
		scanf("%i", &number);
		
		triangulerNumber = 0;
		
		for (n = 1; n <= number; n++ )
			triangulerNumber += n;
		
		NSLog(@"Triangular number %i is %i", number, triangulerNumber);
	}
    
	[pool drain];
    return 0;
}

Number of triangular numbers to compute?
5
What triangular number do you want?
100
Triangular number 100 is 5050
What triangular number do you want?
90
Triangular number 90 is 4095
What triangular number do you want?
80
Triangular number 80 is 3240
What triangular number do you want?
42
Triangular number 42 is 903
What triangular number do you want?
21
Triangular number 21 is 231




Exercise 8

Code: (Objective-C)

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

	long long int number;
	int total;
	
	NSLog(@"Enter your number:");
	scanf("%lli", &number);
	
	// if user enters negative number, convert to positive
	if (number < 0)
		number = -number;
	
	total = 0;
	
	while (number != 0) {
		total += number % 10;
		number /= 10;
	}
    
	NSLog(@"Sum of the digits: %i", total);
	
	[pool drain];
    return 0;
}

Enter your number:
42783321
Sum of the digits: 30