Fibonacci numbers. Simplest algorithm.

fibonacciSimple.cpp

int fibSimple(int elem){

	if(elem < 0){
		return 0;
	}
	
	if(elem == 0){
		return 0;
	}
	
	if(elem == 1){
		return 1;
	}
	
	else{
		int value;
		int prev = 0;
		int cur = 1;

		for(int i = 2; i <= elem; i++){
			value = prev + cur;
			prev = cur;
			cur = value;
		}
		return value;
	}
}