YoungProgrammer

Problem 9: Generate the Fibonacci sequence. Starting with 0, 1 add them up then take the result and add it to the last number and repeat.
0 1 1 2 3 5 8 13 21......

Solution: Problem 7 and 8 were too hard for beginners. You can ignore those 2 problems if you want. But this is not such kind problem. lets we start..
our first number is: 0 , let, int first_num = 0;
our Second number is: 1, let, int second_num = 1;
which is our next one ? it's very easy:
int next_num = first_num + second_num = 0 + 1 = 1;
So far we get: 0 1 1

please observe the code carefully:

#include<stdio.h>

int fibo() {
	int first_num = 0;
	int second_num = 1;
	int next_num;
	int i;
	printf("0 1 ");
	for(i = 0; i<20; i++) {
		next_num = first_num + second_num;
		printf("%d ",next_num);
		first_num = second_num;
		second_num = next_num;
	}
}

int main() {
	fibo();
	return 0;
}

first time:
next_num = first_num + second_num = 0 + 1 = 2
first_num = second num i.e first_num = 1
second_num = next_num = 2

second time:

next_num = first_num + second_num = 1 + 2 = 3
first_num = second num i.e first_num = 2
second_num = next_num = 3

Next time:

next_num = first_num + second_num = 2 + 3 = 5
first_num = second num i.e first_num = 3
second_num = next_num = 5

.....

I think you get it. If not , debug the program or send me a mail.