/*
 * C program to read an English sentence and replace
 * lowercase characters by uppercase and vice-versa.
 * Output the given sentence as well as the converted
 * sentence on two different lines.
 */
#include <stdio.h>
#include <ctype.h>

void main()
{
    char sentence[100];
    int count, ch, i;
    printf("Enter a sentence \n");
    for (i = 0; (sentence[i] = getchar()) != '\n'; i++)
        {
            ;
        }
    sentence[i] = '\0';
    /*  shows the number of chars accepted in a sentence */
    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);
        }
}
/*
*OUTPUT:
Enter a sentence
wELCOME tO sANFOUNDRY
The given sentence is   : wELCOME tO sANFOUNDRY
Case changed sentence is: Welcome To Sanfoundry
*/