C Programming Code Examples C > For Loops and While Loops Code Examples Program to print Fibonacci series in given range Program to print Fibonacci series in given range What is Fibonacci series? Fibonacci series is a series of numbers where the current number is the sum of previous two terms. For Example: 0, 1, 1, 2, 3, 5, 8, 13, 21, ... , (n-1th + n-2th) Logic to print Fibonacci series upto n terms Input number of Fibonacci terms to print from user. Store it in a variable say terms. Declare and initialize three variables, I call it as Fibonacci magic initialization. a=0, b=1 and c=0. Here c is the current term, b is the n-1th term and a is n-2th term. Run a loop from 1 to terms, increment loop counter by 1. The loop structure should look like for(i=1; i<=term; i++). It will iterate through n terms Inside the loop copy the value of n-1th term to n-2th term i.e. a = b. Next, copy the value of nth to n-1th term b = c. Finally compute the new term by adding previous two terms i.e. c = a + b. Print the value of current Fibonacci term i.e. c. #include <stdio.h> int main() { int a, b, c, start, end; /* Input a number from user */ printf("Enter starting term: "); scanf("%d", &start); printf("Enter end term: "); scanf("%d", &end); /* Fibonacci magic initialization */ a = 0; b = 1; c = 0; printf("Fibonacci terms: \n"); /* Iterate through terms */ while(c <= end) { /* If current term is greater than start term */ if(c >= start) { printf("%d, ", c); } a = b; // Copy n-1 to n-2 b = c; // Copy current to n-1 c = a + b; // New term } return 0; }