FANTASTIC C PROGRAM

Check if a given String is Palindrome

#include

#include

#include

void main()

{

    char string[25], reverse_string[25] = {'\0'};

    int  i, length = 0, flag = 0;

    fflush(stdin);

    clrscr();

    printf("Enter a string \n");

    gets(string);

    for (i = 0; string[i] != '\0'; i++)

    {

        length++;

    }

    for (i = length - 1; i >= 0; i--)

    {

       reverse_string[length - i - 1] = string[i];

    }

   

    for (i = 0; i < length; i++)

    {

        if (reverse_string[i] == string[i])

            flag = 1;

        else

            flag = 0;

    }

    if (flag == 1)

        printf("%s is a palindrome \n", string);

    else

        printf("%s is not a palindrome \n", string);

     getch();

}

Output

Enter a string

sanfoundry

sanfoundry is not a palindrome

Enter a string

malayalam

malayalam is a palindrome

Read two Strings & Concatenate the Strings

#include 

#include 

#include 

void main()

{

    char string1[20], string2[20];

    int i, j, pos;

    clrscr();

    memset(string1, 0, 20);

    memset(string2, 0, 20);

    printf("Enter the first string : ");

    scanf("%s", string1);

    printf("Enter the second string: ");

    scanf("%s", string2);

    printf("First string  = %s\n", string1);

    printf("Second string = %s\n", string2);

    for (i = 0; string1[i] != '\0'; i++)

    {

        ;

    }

    pos = i;

    for (j = 0; string2[j] != '\0'; i++)

    {

        string1[i] = string2[j++];

    }

    string1[i] = '\0';

    printf("Concatenated string = %s\n", string1);

    getch();

}

Output

Enter the first string : San

Enter the second string: foundry

First string  = San

Second string = foundry

Concatenated string = Sanfoundry

Replace Lowercase Characters by Uppercase & Vice-Versa

#include 

#include 

#include 

void main()

{

    char sentence[100];

    int count, ch, i;

    clrscr();

    printf("Enter a sentence \n");

    for (i = 0; (sentence[i] = getchar()) != '\n'; i++)

    {

        ;

    }

    sentence[i] = '\0';

    count = i;

    printf("The given sentence is   : %s", sentence);

    printf("\n Case changed sentence is: ");

    for (i = 0; i < count; i++)

    {

        ch = islower(sentence[i])? toupper(sentence[i]) :

tolower(sentence[i]);

        putchar(ch);

    }

    getch();

}

Output

Enter a sentence

wELCOME tO sANFOUNDRY

The given sentence is   : wELCOME tO sANFOUNDRY

Case changed sentence is: Welcome To Sanfoundry

Check if the Substring is present inthe given String
#include
#include
void main()
{
    char str[80], search[10];
    int count1 = 0, count2 = 0, i, j, flag;
    clrscr();
    printf("Enter a string:");
    gets(str);
    printf("Enter search substring:");
    gets(search);
    while (str[count1] != '?')
        count1++;
    while (search[count2] != '?')
        count2++;
    for (i = 0; i <= count1 - count2; i++)
    {
        for (j = i; j < i + count2; j++)
        {
            flag = 1;
            if (str[j] != search[j - i])
            {
                flag = 0;
                break;
            }
        }
        if (flag == 1)
            break;
    }
    if (flag == 1)
        printf("SEARCH SUCCESSFUL!");
    else
        printf("SEARCH UNSUCCESSFUL!");
        getch();
} 


Output


Enter a string: hello
Enter search substring: world
SEARCH UNSUCCESSFUL!
Enter a string: helloworld
Enter search substring:ld
SEARCH SUCCESSFUL!

Accepts two Strings & Compare them
#include 
#include 
void main()
{
    int count1 = 0, count2 = 0, flag = 0, i;
    char string1[10], string2[10];
 
    printf("Enter a string:");
    gets(string1);
    printf("Enter another string:");
    gets(string2);
        while (string1[count1] != '\0')
        count1++;
        while (string2[count2] != '\0')
        count2++;
    i = 0;
 
    while ((i < count1) && (i < count2))
    {
        if (string1[i] == string2[i])
        {
            i++;
            continue;
        }
        if (string1[i] < string2[i])
        {
            flag = -1;
            break;
        }
        if (string1[i] > string2[i])
        {
            flag = 1;
            break;
        }
    }
    if (flag == 0)
        printf("Both strings are equal \n");
    if (flag == 1)
        printf("String1 is greater than string2 \n", string1, string2);
    if (flag == -1)
        printf("String1 is less than string2 \n", string1, string2);
    getch();
}
Output


Enter a string: hello
Enter another string: world
String1 is less than string2
 
Enter a string:object
Enter another string:class
String1 is greater than string2
 
Enter a string:object
Enter another string:object
Both strings are equal