Week5 - De Anza College

```Instructor: Professor Neena Kaushik
Office hours (in AT 203): Mondays: 3:15 to 4:15 p.m.
Wednesdays: 10 to 11 a.m.
and by appointment
Email : [email protected]
Course website: http://www.deanza.edu/faculty/kaushikneena
Lecture: 12:30 - 2:10 p.m. in AT 312 (1:30 – 1:35 p.m. break) (Mondays &
Wednesdays)
Lab: 2:15 - 2:40 p.m. in AT 312 (Mondays & Wednesdays)
Lectures: 9 and 10
Dates: October 20 and October 22
Textbook Chapter: 4
Topics Covered: Standard functions and programming examples
Sentences in quotes have been taken as is from the textbook. The material in these notes
has been prepared by referring the textbook and the slides for the instructor.
“Picture taken from slides for
instructor”
1
The table below gives the declarations of some standard functions and the header files
they are present in.
Function
1
int abs(int number);
stdlib.h
2
long labs(long number);
stdlib.h
3
long long llabs(long long number);
stdlib.h
4
double fabs(double number);
math.h
5
float fabsf(float number);
math.h
6
long double fabsl(long double
math.h
number);
7
double ceil(double number);
math.h
8
float ceilf(float number);
math.h
9
long double ceill(long double
math.h
number);
10
double floor(double number);
math.h
11
float floorf(float number);
math.h
12
long double floorl(long double
math.h
number);
13
double trunc(double number);
math.h
14
float truncf(float number);
math.h
15
long double truncl(long double
math.h
number);
16
double round(double number);
math.h
17
float roundf(float number);
math.h
18
long double roundl(long double
math.h
number);
19
long int lround(double number);
math.h
20
long int lroundf(float number);
math.h
2
21
long int lroundl(long double
math.h
number);
22
long long int llround(double
math.h
number);
23
long long int llroundf(float
math.h
number);
24
long long int llroundl(long double
math.h
number);
25
double pow(double n1, double n2);
math.h
26
float powf(float n1, float n2);
math.h
27
long double powlf(long double n1,
math.h
long double n2);
28
double sqrt(double n1);
math.h
29
float sqrtf(float n1);
math.h
30
long double sqrtlf(long double n1);
math.h
31
void srand(unsigned int seed);
stdlib.h
32
int rand(void);
stdlib.h
33
time_t time(time_t*num)
time.h
The table below lists some standard functions and what it returns
Function
What it returns
1
abs
Absolute value of an integer.
2
labs
Absolute value of a number of the type
long.
3
llabs
Absolute value of a number of the type
long long.
4
fabs
Absolute value of a number of the type
double.
5
fabsf
Absolute value of a number of the type
float.
3
6
fabsl
Absolute value of a number of the type
long double.
7
ceil
Smallest integral value (as a type
double) greater than or equal to a
number.
8
ceilf
Smallest integral value (as a type
float) greater than or equal to a
number.
9
ceill
Smallest integral value (as a type long
double) greater than or equal to a
number.
10
floor
Largest integral value (as a type
double), that is equal to or less than a
number.
11
floorf
Largest integral value (as a type
float), that is equal to or less than a
number.
12
floorl
Largest integral value (as a type long
double), that is equal to or less than a
number.
13
trunc
Integral (as a double) in the direction
of 0.
14
truncf
Integral (as a float) in the direction
of 0.
15
truncl
Integral (as a long double) in the
direction of 0.
16
round
Nearest integral value (as type double).
17
roundf
Nearest integral value (as type float).
18
roundl
Nearest integral value (as type long
double).
19
lround
Nearest integral value (as type long
4
int).
20
lroundf
Nearest integral value (as type long
int).
21
lroundl
Nearest integral value (as type long
int).
22
llround
Nearest integral value (as type long
long int).
23
llroundf
Nearest integral value (as type long
long int).
24
llroundl
Nearest integral value (as type long
long int).
25
pow
Value of x raised to power y as type
double.
26
powf
Value of x raised to power y as type
float.
27
powlf
Value of x raised to power y as type
long double
28
sqrt
Non-negative square root of a number as
type double.
29
sqrtf
Non-negative square root of a number as
type float.
30
sqrtlf
Non-negative square root of a number as
type long double.
31
srand
Void (Creates starting side for a random
number series).
32
rand
A pseudorandom integer between 0 and
RAND_MAX.
33
time
The current calendar time as time_t
object
Here is the function usage and the return values.
5
Function usage
Return value
1
abs(3);
3
2
labs(3);
3
3
llabs(3);
3
4
fabs(-3.4);
3.4
5
fabsf(-3.4);
3.4
6
fabsl(-3.4);
3.4
7
ceil(-1.9);
-1.0
ceil(1.1);
2.0
8
ceilf(-3.2);
-3.0
9
ceill(4.3);
5.0
10
floor(-1.1);
-2.0
floor(1.9);
1.0
11
floorf(-1.1);
-2.0
12
floorl(-1.2);
-2.0
13
trunc(-1.1);
-1.0
trunc(1.9);
1.0
14
truncf(1.3);
1.0
15
truncl(2.1);
2.0
16
round(-1.1);
1.0
17
roundf(1.9);
2.0
18
roundl(2.4);
2.0
19
lround(1.0);
1.0
20
lroundf(1.3);
1.0
21
lroundl(1.4);
1.0
22
llround(1.5);
2.0
23
llroundf(1.6);
2.0
24
llroundl(-1.6);
-2.0
25
pow(3.0,4.0);
81.0
26
powf(3.4,2.3);
16.687893
6
27
powlf(2.0,2.0);
4.0
28
sqrt(25);
5.0
29
sqrtf(81);
9.0
30
sqrtlf(196);
14.0
31
srand(time(NULL)); The seed is set
32
rand();
A pseudo random number
33
time(NULL);
Number of seconds since January 1,
1970
Program 1
Creating random numbers
/******************************************************
** Program written by: Taken from textbook
** Inputs:
None
** Returns: An Integer
** What the program does: It prints random numbers
******************************************************/
#include “stdafx.h”
#include <stdio.h>
#include <time.h>
#include <conio.h>
int main(void)
{
srand(time(NULL));
printf(“\n %d”, rand());
printf(“\n %d”, rand());
printf(“\n %d”, rand());
getch();
7
return 0;
}
Program 2
Creating pseudo-random numbers
/******************************************************
** Program written by: Taken from textbook
** Inputs:
None
** Returns: An Integer
** What the program does: It prints pseudorandom numbers
******************************************************/
#include “stdafx.h”
#include <stdio.h>
#include <conio.h>
int main(void)
{
srand(997);
printf(“\n %d”, rand());
printf(“\n %d”, rand());
printf(“\n %d”, rand());
getch();
return 0;
}
Program 3
Generate random numbers in the range 10 to 20
/******************************************************
** Program written by: Taken from textbook
** Inputs:
None
** Returns: An Integer
8
** What the program does: It prints random numbers in range
of 10 to 20
******************************************************/
#include “stdafx.h”
#include <stdio.h>
#include <time.h>
#include <conio.h>
int main(void)
{
int range;
srand(time(NULL));
range = (20-10)+1;
printf(“\n %d”, rand() % range + 10);
printf(“\n %d”, rand() % range + 10);
printf(“\n %d”, rand() % range + 10);
getch();
return 0;
}
Program 4
Generate random numbers in the range 0.0 to 1.0
/******************************************************
** Program written by: Taken from textbook
** Inputs:
None
** Returns: An Integer
** What the program does: It prints random numbers in range
of 0.0 and 1.0
******************************************************/
#include “stdafx.h”
#include <stdio.h>
9
#include <time.h>
#include <conio.h>
#include<time.h>
int main(void)
{
float x;
srand(time(NULL));
x=(float)rand()/RAND_MAX;
print(“\n%f”, x);
getch();
return 0;
}
10
```