编辑代码

#include <stdio.h>

int Fibonacci1(int num){
    if (num<1){
        return 0;
    }
    if (num==1||num==2){
        return num;
    }
    int result1=1,result2=2,result=0;
    for (int i=3;i<=num;i++){
        result=result1+result2;
        result1=result2;
        result2=result;
    }
    return result;
}

int Fibonacci2(int num){
    if (num==1||num==2){
        return num;
    }
    return Fibonacci2(num-1)+Fibonacci2(num-2);
}

int main () {
    printf("递推：%d\n",Fibonacci1(6));
    printf("递归：%d",Fibonacci2(6));
    return 0;
}