fibonacci series in c using function

                                    #include <stdio.h>
int main() {
    int i, n, t1 = 0, t2 = 1, nextTerm;
    printf("Enter the number of terms: ");
    scanf("%d", &n);
    printf("Fibonacci Series: ");

    for (i = 1; i <= n; ++i) {
        printf("%d, ", t1);
        nextTerm = t1 + t2;
        t1 = t2;
        t2 = nextTerm;
    }

    return 0;
}

                                    #include <stdio.h>
int main() {
    int t1 = 0, t2 = 1, nextTerm = 0, n;
    printf("Enter a positive number: ");
    scanf("%d", &n);

    // displays the first two terms which is always 0 and 1
    printf("Fibonacci Series: %d, %d, ", t1, t2);
    nextTerm = t1 + t2;

    while (nextTerm <= n) {
        printf("%d, ", nextTerm);
        t1 = t2;
        t2 = nextTerm;
        nextTerm = t1 + t2;
    }

    return 0;
}

                                    #include<stdio.h>

void fibonacciSeries (int range);

void main()
{
   int range;

   printf("Enter range: ");
   scanf("%d", &range);

   printf("\nThe Fibonacci series is: \n");

   fibonacciSeries(range);

}

void fibonacciSeries(int range)
{
   int a=0, b=1, temp;

   while (a<=range)
   {
     printf("%d\t", a);
     temp = a+b;
     a = b;
     b = temp;
   }

}

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

int main() {
	long int a = 1,b = 2, c, d, cont = 0;
	double e, f;
	
	printf("Fibonacci fino a: ");
	scanf("%ld", &c);
	
	while(b < c)
	{
		cont ++;
		printf("\n%ld", b);
		d = a;
		a = b;
		b = b + d;
	}
	
	f = (double)b / (double)a;
	
	e = (double)cont / (double)c * (double)100;
	
	printf("\n\nOttenuto: %lf\nPercentuale: %lf\n\n\n", f, e);
	
	system("pause");
}