rt，此代码会崩溃。错误的地方我已经找出来了，求调%%%悬赏关注

#include<bits/stdc++.h>
using namespace std;
#define maxn 100000
inline int read() {
	int x=0,f=1;
	char ch=getchar();
	while(ch<'0'||ch>'9') {
		if(ch=='-') {
			f=-1;
		}
		ch=getchar();
	}
	while(ch>='0'&&ch<='9') {
		x=(x<<1)+(x<<3)+(ch^48);
		ch=getchar();
	}
	return x*f;
}
inline void write(int x) {
	if(x<0)
		putchar('-'),x=-x;
	if(x>9) {
		write(x/10);
	}
	putchar(x%10 +'0');
}
struct bigint {
	int len,a[maxn];
	inline bigint(int x=0) {
		memset(a,0,sizeof(a));
		for(len=1; x; len++) {
			a[len]=x%10;
			x/=10;
		}
		len--;
	}
	int &operator [](int i) {
		return a[i];
	}
	inline void flatten(int l) {
		len=l;
		for(int i=1; i<len; i++)a[i+1]+=a[i]/10,a[i]%=10;
		while(!a[len])len--;
	}
	inline void putbig() {
		for(int i=max(len,1); i>=1; i--) {
			write(a[i]);
		}
	}
};

bigint operator+(bigint a,bigint b){
	bigint c;
	int len =max(a.len,b.len);
	for(int i=1;i<=len;i++){
		c[i]+=a[i]+b[i];
	}
	c.flatten(len+1);
	return c;
}
int main() {
	bigint l1=1;
	bigint l2=0;
	bigint nw=0;
	int b=read();
	bigint t; 
	for(int i=0; i<b; i++) {
		t=nw;
		nw=l1+l2;//error line!
		l2=l1;
		l1=t;
	}
	nw.putbig();
	return 0;
}