refactor

9 Algorithms Job Interview/codes/5 array/fibonacci.c

@@ -0,0 +1,57 @@
+
+#include "stdio.h"
+#include "time.h"
+
+
+
+int fibonacci(int n){
+
+	int result[2] = {0,1};
+	if (n<2)
+	{
+		return result[n];
+	}
+
+	return fibonacci(n-1)+fibonacci(n-2);
+}
+
+
+// 循环
+int fibonacci2(int n){
+
+	int result[2] = {0,1};
+
+	if ( n<2 )
+	{
+		return result[n];
+	}
+
+	int fibOne=0;
+	int fibTwo=1;
+	int fibN;
+	for (int i = 2; i < n; ++i)
+	{
+		fibN = fibOne + fibTwo;
+		fibOne = fibTwo;
+		fibTwo = fibN;
+				
+	}	
+
+	return fibN;
+}
+
+
+
+int main(){
+
+	int start,end;
+	long result;
+
+	start = clock();
+	result=fibonacci2(40);
+	end = clock();
+	printf("%ld %.6fs",result,(double)(end-start)/CLOCKS_PER_SEC);
+
+	return 0;
+}
+