1.FSM

#include <stdio.h>
#include <string.h>

int hasEqualAB(const char* input) {
    int count = 0;

    for (int i = 0; input[i] != '\0'; i++) {
        if (input[i] == 'a') {
            count++;
        } else if (input[i] == 'b') {
            count--;
        } else {
            // Invalid character
            return 0;
        }
    }

    return count == 0;
}

int main() {
    char str[100];

    printf("Enter a string (only a and b): ");
    scanf("%s", str);

    if (hasEqualAB(str)) {
        printf("Accepted: Equal number of 'a' and 'b'\n");
    } else {
        printf("Rejected: Unequal number of 'a' and 'b'\n");
    }
return 0;
}