12.17 Tutorial10

intro-to-computer-science-gtiit-tutorial-10-2024.pdf

1. Programs Outputs

1.1

What is the output of this C program?

main(){
  int i;
  char c[] = "Nice";
  for(i=0; i<5; i++)
    printf("%c ",c[i]);
}

N i c e

1.2

What is the output of this C program?

void go(int a[], int j){
  printf("%d ", a[j]);
}

main(){
  int i;
  int a[5] = {3,3,7,3,8};
  int b[5] = {2,2,4,2,2};
  for(i=0; i<5; i++)
    go(b,i);
  go(a,b[i-2]));
}

2 2 4 2 2 7

2. Functions Definitions

2.1

In a C file, define the following functions:

void printArr(const int a[], int n) - prints an array of size n on a single line and prints a newline character.
void fillRandom(int a[], int n) - fills the array with random values from 0 to 99. This function assumes that the calling environment has already initialized the random number generator with srand().
void reverse(const int a[], int b[], int n) - copies the contents of array a in reverse order into array b (n is the size of both arrays).

Use the following main() function to test your functions:

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

#define S 10
main(){
  srand(time(NULL));
  int x[S];
  int y[S];
  fillRandom(x,S);
  reverse(x,y,S);
  printArr(x,S);
  printArr(y,S);
}

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

#define S 10

void printArr(const int a[], int n) {
    for(int i = 0; i < n; i++)
        printf("%d ", a[i]);
    printf("\n");
}

void fillRandom(int a[], int n) {
    for(int i = 0; i < n; i++)
        a[i] = rand() % 100;
}

void reverse(const int a[], int b[], int n) {
    for(int i = 0; i < n; i++)
        b[i] = a[n - i - 1];
}

int main(){
    srand(time(NULL));
    int x[S];
    int y[S];
    fillRandom(x,S);
    reverse(x,y,S);
    printArr(x,S);
    printArr(y,S);
}

2.2

In a C program, define the following functions:

int isLower(char c) - returns 1 if c is a lowercase letter, 0 otherwise.
int isUpper(char c) - returns 1 if c is an uppercase letter, 0 otherwise.
char modChar(char c) - returns the uppercase counterpart if given a lowercase letter, and vice versa. If given any other kind of character, it returns the same character. This function must call isLower() and isUpper().
void modString(char str[]) - applies the function modChar() to the zero-terminated string str, character by character.

Use the following main() function to test your program:

main(){
  char input[100];
  gets(input);
  modString(input);
  printf("%s\n", input);
}

Example of execution:

$ tcc -w -run strings.c
Hello World!
hELLO wORLD!

#include<stdio.h>

int isLower(char c) {
    if(c >= 'a' && c <= 'z') 
        return 1;
    else
        return 0;
}

int isUpper(char c) {
    if(c >= 'A' && c <= 'Z') 
        return 1;
    else
        return 0;
}

char modChar(char c) {
    if(isUpper(c)) {
        c = c + 'a' - 'A';
        return c;
    } 
    else if(isLower(c)) {
        c = c - 'a' + 'A';
        return c;
    }
    else 
        return c;
}

void modString(char str[]) {
    for(int i = 0; str[i] != '\0'; i++) {
        str[i] = modChar(str[i]);
    }
}

int main(){
    char input[100];
    gets(input);
    modString(input);
    printf("%s\n", input);
}

2.3

In a C program, define a function: int search(const int a[], int n, int v) This function performs a linear search of the value v in the array a of size n. It returns:

The smallest value i such that v \=\= a[i], if such i exists, otherwise
The symbolic constant value ERROR (defined as -1).

In the same program, define a main() function that declares and initializes an array, and does two calls to search() , to show both behaviors of the function.

#include<stdio.h>

int search(const int a[], int n, int v) {
    for(int i = 0; i < n; i++) {
        if(a[i] == v)
            return 1;
    }
}

int main() {
    int array[64];
    int number = 0;
    int curr;

    scanf("%d", &curr);
    array[0] = curr;
    for(int i = 0; curr != 250250250; i++) {
        scanf("%d", &curr);
        array[i + 1] = curr;
        number++;
    }

    printf("What value do you want to search: ");
    int need_search;
    scanf("%d", &need_search);
    if(search(array, number, need_search) == 1)
        printf("Yes");
    else
        printf("Error");

}

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