我想用 goto码来实现这个递归 来个大佬给给思路 （还要用到进栈和出栈）

Question

int f(int N)
{
if (N==0) return 0;
else if (N==1) return 1;
else return f(n-1)+f(n-2);
}

        例如下面这样来实现阶乘
        int fact(int n)

{
int num=1;
stack S;
L:
if(n>0)
{
S.push(n);
n=n-1;
goto L;
M:
num*=S.top();
S.pop();
}
if(!S.empty())
{
goto M;
}
return num;
}

Answer 1

// Q755200.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

#include <stdio.h>

int stack[1000];
int curr = 0;

void push(int n)
{
    if (curr >= 1000) printf("stack overflow!!");
    stack[curr++] = n;
}

int pop()
{
    if (curr < 0) printf("stack empty!!!");
    return stack[--curr];
}

int f(int n1)
{
    int a;
    int b;

    push(0);
    push(n1);
    push(0);

callstart:
    int pos = pop();
    int n = pop();
    if (n == 1 || n == 2)
    {
        push(1);
        if (pos == 1) goto endcall1;
        if (pos == 2) goto endcall2;
        if (pos == 0) return 1;
    }
    push(n);
    push(a);
    push(b);
    push(pos);
    push(n - 1);
    push(1);
    goto callstart;
endcall1:
    a = pop();
    pos = pop();
    b = pop();
    pop();
    n = pop();
    push(n);
    push(a);
    push(b);
    push(pos);
    push(n - 2);
    push(2);
    goto callstart;
endcall2:
    b = pop();
    pos = pop();
    pop();
    a = pop();
    n = pop();
    push(a + b);
    if (pos == 1) goto endcall1;
    if (pos == 2) goto endcall2;
    if (pos == 0) return a + b;
}

int main()
{
    for (int i = 0; i < 10; i++)
        printf("%d ", f(i + 1));
    return 0;
}