不要管标题，我这是求助帖。。。主要是因为没人看

我的代码哪里写的不规范,cf输出和本地不一样，求助大佬

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 505;

int n;
int a[N], b[N];
int res = -1;
bool st[N];

int ck()
{
	int len;
	for (int i = 3; i <= n + 1; i ++ )
	  if (b[i] != b[i - 1] + b[i - 2])
	  {
	  	len = i - 1;
	  	break;
	  }
	
	return len;
}

void dfs(int u)
{
	if (u == n + 1)
	{
		res = max(res, ck());
		return;
	}
	
	for (int i = 1; i <= n; i ++ )
	  if (!st[i])
	  {
	  	b[u] = a[i];
	  	st[i] = 1;
	  	dfs(u + 1);
	  	st[i] = 0;
	  }
}

int main()
{
//	freopen("fibonacci.in", "r", stdin);
//	freopen("fibonacci.out", "w", stdout);
	
	scanf("%d", &n);
	if (n < 2)
	{
		printf("0\n");
		return 0;
	}
	if (n == 2)
	{
		printf("2\n");
		return 0;
	}
	for (int i = 1; i <= n; i ++ )  scanf("%d", &a[i]);
	sort(a + 1, a + n + 1);
    dfs(1);
	
	printf("%d\n", res);
	return 0;
}