Fibonacci game

There is a pile of stones with a number of n (n>=2). Both sides of the game take turns to take stones. The rules are as follows:

1) The first mover cannot take all the stones at the first time, at least one stone is taken;

2) The number of stones that can be taken each time after that is at least 1, and at most 2 times the number of stones the opponent just took.

It is agreed that the person who takes the last stone will be the winner.

Conclusion: When n is a Fibonacci number, you must lose.

f[i]：1,2,3,5,8,13,21,34,55,89……

 nyoj 385

#include<stdio.h>
long long a[110]={0,1};
int main(){
	long long n;
	for(int i=2;i<100;i++){
		a[i]=a[i-1]+a[i-2];
	}
	while(scanf("%lld",&n)!=EOF){
		int flag=0;
		for(int i=1;i<100;i++){
			if(a[i]==n){
				flag=1;
				break;
			}
		}
		if(flag)
		printf("No\n");
		else
		printf("Yes\n");
	}
	return 0;
}