#include <jni.h>
#include <string>

extern "C"
JNIEXPORT jint JNICALL
Java_com_tpandroid_fibonacci_MainActivity_fibonacci(JNIEnv *env, jobject instance, jint number)
{

    if (number <= 0)
    {
        return 0;
    }
    else if (number == 1)
    {
        return 1;
    }
    else if (number > 1)
    {
        jlong moins_deux = 0;
        jlong moins_un = 1;
        jlong answer = 0;
        for (int i = 2; i <= number; i++)
        {
            answer = moins_deux + moins_un;
            moins_deux = moins_un;
            moins_un = answer;
        }
        return answer;
    }

    return number;
}