COMP1911 Week 03 Tutorial Questions

Consider the two code snippets below, what will be the output after execution of each of the programs for inputNum = 3.

int inputNum, i; 

printf("Enter a number: "); 
scanf("%d", &inputNum); 

i = inputNum; 

if(i <= 5){
  printf("%d\n", i * i); 
  i++; 
}

int inputNum, i; 

printf("Enter a number: "); 
scanf("%d", &inputNum); 

i = inputNum; 

while(i <= 5){
  printf("%d\n", i * i); 
  i++; 
}

Discuss the errors in these while loops

int i;

while (i < 100) {
    printf("%d\n", i);
    i = i + 1;
}

int i = 0;
int j = 0;

while (j = 1 || i < 100) {
    printf("%d\n", i);
    i = i + 1;
}

int i = 0;
int n = 10;
while (i < n) {
    printf("%d\n", i);
    n = n + i;
    i = i + 1;
}

int i = 0;
while (i < 10)
    printf("%d\n", i);
    i = i + 1;

- Using pseudo code, write an algorithm for printing the numbers from k down to 1 together with their squares. You can assume k is 10
- Translate the pseudo code you have just written into a functioning C program. Use a while loop.
- Modify your C code so that your program, after printing a number and its square on a line, prints the string "Number is even" if the number (not its square) is even and otherwise prints the string "Number is odd" if the number is odd.
Write a program that reads in an integers and prints out that many asterisks, each on a new line.
```
./asterisks
Please enter an integer: 5
*
*
*
*
*
```

Write a program that repeatedly reads in integers until a negative integer is read in. Your program should print out how many integers were read in. For example:

./readInts
Please enter some integers:
10 100 999 78 -3
You entered 4 integers

./readInts
Please enter some integers:
1 2 3 4 5 6 7 8 9 
10 11 12 -9
You entered 12 integers

Write a C program multipleOfTen.c which reads 2 integers and then prints all multiples of ten between those numbers.
Write a C program log10.c which reads a positive integer, and calculates the integer part of its base 10 logarithm. Hint: repeatedly divide by 10.

Consider the following code

#include <stdio.h>

int main(void) {
    int number;
    int row, column;

    // Obtain input
    printf("Enter number: ");
    scanf("%d",&number);

    row = 1;
    while (row <= number) {
        column = 1;
        while (column <= number) {
            printf("*");
            column = column + 1;
        }
        printf("\n");
        row = row + 1;
    }

    return 0;
}

What is the output if the user types in the number 5?

Modify the program so that it prints out a triangle that consists of number asterisks eg

Enter number: 5
    *
   **
  ***
 ****
*****

Write a program diagonal.c that reads an integer and prints the following pattern:

./diagonal
Enter an integer: 10
*
 *
  *
   *
    *
     *
      *
       *
        *
         *

Write a program cross.c that reads an integer and prints the following pattern. You may assume your input is a positive integer >= 5
```
./cross
Enter size: 5
*---*
-*-*-
--*--
-*-*-
*---* 
```
Write a program that reads two integers (height x length) and prints a rectangular, asterisk outline with the specified dimensions, for example:
```
./rectangle
Enter rectangle height and length: 3 5
*****
*   *
*****
```

Design and write a program that an integers and prints a diamond, asterisk outline with the specified side length, for example:

./diamond
Enter side length: 3
  *
 * *
*   *
 * *
  *
./diamond
Enter side length: 6
     *
    * *
   *   *
  *     *
 *       *
*         *
 *       *
  *     *
   *   *
    * *
     *

Write a program that reads in an integer n, and then prints a nxn multiplication table. For example:

./multiplicationTable
Enter multiplication table size: 5
 1|   1    2    3    4    5
 2|   2    4    6    8   10
 3|   3    6    9   12   15
 4|   4    8   12   16   20
 5|   5   10   15   20   25

What is a function? Discuss the main features of functions? What is the type of a function? What is a function prototype? What are some of the benefits of using functions?

A student wrote the following code to read in a number, n and print out n asterisks.

void getSquare(void);

int main(void){
    int n;
    printf("Enter a number ");
    scanf("%d",&n);    
    getSquare();
    printf("The square of %d is %d\n", n, sqr);
    return EXIT_SUCCESS;
}

int getSquare(void) {
    int i;
    int count = 1;

    i = 0;
    while ( i < n ) {
        count *= n
        i = i + 1;
    }
    printf("\n");    
}

It had the following compile time error:

getSquare.c:17:17: error: use of undeclared identifier 'n'
    while ( i < n ) {

What is wrong with the code? How can we fix it?