APS105 Tutorial 4 - Midterm Solutions

Official Midterm Solutions are online, but here is the files I will use to show how the solution works

Q14

/*
* File: main.c
* Author: kmingk
*
* Created on October 18, 2015, 12:46 PM
*/

#include <stdio.h>
#include <stdlib.h>

/* Develop a program that would continuously ask the users for characters.
* When a user enters NAN, it should print out pattern found, and should be
* able to recognize NANAN as two separate instances.
*
* Program should end when F is entered
*/
int main(int argc, char** argv) {
// Declare Variables
char c1, c2; // c1 - previous input, c2 - the input before c1
char currentInput;

// Initialize variables to non-important characters
c1 = 'C';
c2 = 'C';
currentInput = 'C';

// Keep looping for user input of characters
do {
printf ("Please enter a character: ");
scanf (" %c", &currentInput);
// Proper way to do this. Keeps a correct running history
if ((currentInput == 'N') && (c1 == 'A') && (c2 == 'N')) {
printf ("Pattern NAN Found\n");
}

// Keep a running history of characters
c2 = c1;
c1 = currentInput;

// Incorrect way other people are doing this - This misses NANAN or NNAN
// if (currentInput == 'N') {
// printf ("Please enter a character: ");
// scanf (" %c", &c1);
// if (c1 == 'A') {
// printf ("Please enter a character: ");
// scanf (" %c", &c2);
// if (c2 == 'N') {
// printf ("Pattern NAN Found\n");
// }
// }
// }
} while (currentInput != 'F');

printf ("Done!\n");
return (EXIT_SUCCESS);
}

Q11

/*
* File: main.c
* Author: kmingk
*
* Created on October 18, 2015, 1:21 PM
*/

#include <stdio.h>
#include <stdlib.h>

/* Create a function that takes in a user inputted integer and reverse the digits
* must use a function
*
*/

// 12345 --> 54321
// 21452 --> 25412
// 12340 --> 04321
int reverseDigit (int input) {
// We want to start with output = 0 since we use it later on, so
// make sure its initialized properly
int output = 0;
// we want to stop once we are done with the "1's" digit.
// Extra: Try changing loop so it is >= 10, 100, what happens?
while (input >= 1) {
int remainder; // temp variable to store the remainder
remainder = input%10;
input = input/10; // our loop relies on us to continues divide input

output = output*10 + remainder;
}
// Example of how this works:
// 12345 --> input
// 12345%10 --> 5 + output*10 (0*10) = 5 = output
// 12345/10 --> 1234 --> input
// 1234%10 --> 4 + output*10 (5*10) = 54 = output
// 1234/10 --> 123 --> input
// 123%10 --> 3 + output*10 (54*10) = 543 = output
// 123/10 --> 12
return output;
}

int main(int argc, char** argv) {
int userInput;
int output;

// Get User Input
printf ("Enter Number: ");
scanf("%d", &userInput);

output = reverseDigit (userInput);

printf ("Output: %d\n", output);
return (EXIT_SUCCESS);
}

Q13

/*
* File: main.c
* Author: Kmingk
*
* Created on October 18, 2015, 1:03 PM
*/

#include <stdio.h>
#include <stdlib.h>

/* Program to accept a number input from the user (0-9)
* The program will then output a pattern that is ten rows in total and ten
* digits.
* The pattern will shift to the left
*
* Example:
* Input: 0
* 0123456789
* 1234567890
* 2345678901
* 3456789012
* 4567890123
* 5678901234
* 6789012345
* 7890123456
* 8901234567
* 9012345678
*
* Input: 3
* 3456789012
* 4567890123
* 5678901234
* 6789012345
* 7890123456
* 8901234567
* 9012345678
* 0123456789
* 1234567890
* 2345678901
*
*/
int main(int argc, char** argv) {

// Declare Variables
int userInput = 0;
int row, col;
// Get User Input
printf ("Please enter index (0-9): ");
scanf ("%d", &userInput);

// Go through the 10 rows
for (row = 0; row < 10; row++) {
// Go through all the columns
for (col = 0; col < 10; col++) {
// Uncomment each of the lines (1-4) one by one to see the effect
// 1: Printing out col will repeat me 0123456789 for all rows
// printf ("%d", col);

// 2: Printing out col+row --> starting number increases by 1 each
// row, spacing added for visibility
// printf ("%d ", (col+row));

// 3: Printing out col+row%10 --> Gets me the shifted pattern
// printf ("%d", (col+row)%10);

// 4: Adding in the effect of userInput
// printf ("%d", (col+row+userInput)%10);

// Extra: What happens if i print newline here?
// A: Adds newline after every digit! --> not good
// printf ("\n");
}
// end of columns, print newline
printf ("\n");
}
return (EXIT_SUCCESS);
}

APS105 Tutorial 3

Mainly covers a basic loop and checks and conditions to get out of the loop.

Can use "continue" to get out of the loop, but usually there are ways to do it without in a cleaner way.

/* 
 * File: main.c
 * Author: user
 *
 * Created on October 3, 2015, 2:03 AM
 */

#include <stdio.h>
#include <stdlib.h>

/*
 * Create a program which repeatedly asks a user for a grade between 0 and 100 
 * (inclusive) and computes the minimum grade, the maximum grade and the average
 * grade.The grades may be entered as floating point numbers
 * and the program should ask for another grade when presented with on greater
 * than 100.Any grade less than 0 should case the program to terminate.Prior
 * to termination, the program should print the min, max, avg grade. The program
 * cannot ask the user for the number of grades directly.
 *
 * Inputs
 *inputGrade - double (0-100) >0 is invalid/less than 0 ends program 
 * Outputs
 *minGrade - double smallest grade
 *maxGrade - double largest grade
 *avgGrade - double average grade
 */
int main(int argc, char** argv) {
// Declare and Initialize variables
double inputGrade, minGrade, maxGrade, avgGrade, sumGrades;
int numGrades;
minGrade = 100;
maxGrade = 0;
numGrades = 0;
sumGrades = 0;

// Loop through and repeatedly ask user for grades
// determine running min/max/avg while we loop
// Exit conditions: inputGrade Less than 0
printf ("Enter a grade: ");
scanf ("%lf", &inputGrade);
while (inputGrade >= 0) {
// can be another way to check for valid input
//if (inputGrade > 100) {
//// ask user for input
//continue;
//}

// Check Valid Input
if (inputGrade <= 100) {
// Calculate running statistics 
if (inputGrade > maxGrade) {
maxGrade = inputGrade; // calculate running Max
} 
if (inputGrade < minGrade) {
minGrade = inputGrade; // calculate running Min
}
// Running total of grades and number of grades --> get average at the end
numGrades += 1;
sumGrades += inputGrade;
}
printf ("Enter a grade: ");
scanf ("%lf", &inputGrade);
}

// compute average
avgGrade = sumGrades / numGrades;

// Output results
if (numGrades > 0) {
printf ("Number of grades: %d\n", numGrades);
printf ("Minimum Grade: %lf\n", minGrade);
printf ("Maximum Grade: %lf\n", maxGrade);
printf ("Average Grade: %lf\n", avgGrade);
} else {
printf ("Didn't enter grades\n")
}
return (EXIT_SUCCESS);
}

APS105 Tutorial 2

Mainly covers conditional statements, but once again going from code to program. There are several key things to note here:

Constants are used to instead of "magic" numbers.
Math library is used here
- Netbeans --> Project properties --> Linker --> Libraries --> Standard libraries

/* 
 * File: main.c
 * Author: Kmingk
 *
 * Created on September 27, 2015
 */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

/* Tutorial 2 - Advanced output
 * 
 * Program Description:
 * Build a program that takes a dollar (and cents) value less than 20
 * and rounds the value to the nearest nickel.It then computes the
 * smallest number of total bills and coins that sum to that rounded value
 * 
 * Inputs:
 *rawAmount - Double
 * Outputs:
 *roundedAmount - Double
 *numTens - int
 *numFives- int
 *numOnes 
 *numQuarters
 *numDimes
 *numNickels
 */
int main(int argc, char** argv) {
// Variable and Constants Declaration
const double TEN= 10;
const double FIVE = 5;
const double ONE= 1;
const double QRTR = 0.25;
const double DIME = 0.1;
const double NICKEL = 0.05;

double rawAmount, roundedAmount, savedRoundedAmount;
int numTens, numFives, numOnes, numQuarters, numDimes, numNickels;
 
// Get monetary value from user
printf ("Enter Value: ");
scanf ("%lf", &rawAmount);
if (rawAmount < 0) {
exit()
}

// Round value to nearest nickel
// round the normalized amount rawAmount/Nickels --> then multiply
// by the value of a nickel to get the rounded to nickel value
roundedAmount = rint(rawAmount / NICKEL) * NICKEL;
savedRoundedAmount = roundedAmount;
//printf ("%lf", roundedAmount);

// Calculating the number of each denomination, roundedAmount keeps a 
// rolling total of the remainder
numTens = roundedAmount/TEN; 
roundedAmount = roundedAmount - TEN*numTens; 
numFives = roundedAmount/FIVE; 
roundedAmount = roundedAmount - FIVE*numFives;
numOnes = roundedAmount/ONE;
roundedAmount = roundedAmount - ONE*numOnes;
numQuarters = roundedAmount/QRTR;
roundedAmount = roundedAmount - QRTR*numQuarters;
numDimes = roundedAmount/DIME;
roundedAmount = roundedAmount - DIME*numDimes;
numNickels = roundedAmount/NICKEL;
roundedAmount = roundedAmount - NICKEL*numNickels;

// Output Raw and Rounded amount with change needed
printf ("Raw Value: $%0.2lf\n", rawAmount);
printf ("Rounded Value $%0.2lf\n", savedRoundedAmount);
printf ("# Tens: %d\n", numTens);
printf ("# Fives: %d\n",numFives);
printf ("# Dollars: %d\n",numOnes);
printf ("# Quarters: %d\n", numQuarters);
printf ("# Dimes: %d\n",numDimes);
printf ("# Nickels: %d\n",numNickels);
}

APS105 Tutorial 1

The code is meant to take a program description (in comments) and convert that to code. Mainly uses boundary checks and conditions and input/output

If statement order matters --> Try for yourself and change the ordering of the if statement
The & in front of the variable means that we are passing an address. This is needed for scanf.

/* 
 * File: main.c
 * Author: user
 *
 * Created on September 21, 2015, 9:11 AM
 */

#include <stdio.h>
#include <stdlib.h>

/*
 * Build a program that computes a person's Body Mass Index. BMI is computed as 
 * BMI = Person's Weight (KG)/ Person's Height (m) ^2 and tell if a person is
 * overweight.Overweight BMI is 25.
 * 
 */

int main(int argc, char** argv) {
// Get user's height and weight
double height, weight, BMI;
printf("Please enter the height(m): ");
scanf("%lf", &height);
printf("Please enter the weight(kg): ");
scanf("%lf", &weight);

// Compute the BMI: BMI = w/h^2
BMI = weight / (height * height);

// Output BMI
printf("Your BMI \tis: %20.4lf\n", BMI);

// Tell if the user is overweight or not
if (BMI >= 40) {
printf("See a doctor?\n");
} else if (BMI >= 25) {
printf("Overweight\n");
} else {
printf("Normal\n");
}

return (EXIT_SUCCESS);
}