The Program in C that uses a function to determine whether a given positive integer is a fibonacci number or not is given below:
#include<stdio.h>
int isFibonacci(int num) {
int a = 0, b = 1, c = a + b;
while(c < num) {
a = b;
b = c;
c = a + b;
}
return (c == num);
}
int main() {
int num;
printf("Enter a positive integer: ");
scanf("%d", &num);
if(isFibonacci(num))
printf("%d is a Fibonacci number.", num);
else
printf("%d is not a Fibonacci number.", num);
return 0;
}
Output:
Enter a positive integer: 8
8 is a Fibonacci number.
Pro-Tips💡
This program prompts the user to enter a positive integer, and then uses the isFibonacci function to determine if the number is a Fibonacci number or not.
The function uses a while loop to generate the Fibonacci sequence until a number greater than or equal to the input number is reached.
If the generated number is equal to the input number, the function returns 1 (true), otherwise it returns 0 (false).
Learn C-Sharp ↗
C-sharp covers every topic to learn about C-Sharp thoroughly.
Learn C Programming ↗
C-Programming covers every topic to learn about C-Sharp thoroughly.
Learn C++ Programming↗
C++ covers every topic to learn about C-Sharp thoroughly.