为什么RE

#include<bits/stdc++.h>
using namespace std;
long long a, b;
bool fa = 0;
long long cnt = 0;
long long d[1000000];
void dfs(int x){
	if(x > b) return;
	if(x == b){
		fa = 1;
		cout << "YES" << endl;
		cout << cnt << endl;
		for(int i = 1; i <= cnt; ++i){
			cout << d[i] << " ";
		}
		return;
	}
	cnt++;
	d[cnt] = x * 2;
	dfs(x * 2);
	d[cnt] = 0;
	cnt--;
	cnt++;
	d[cnt] = x * 10 + 1;
	dfs(x * 10 + 1);
	d[cnt] = 0;
	cnt--;
}
int main(){
	cin >> a >> b;
	d[1] = a;
	cnt++;
	dfs(a);
	if(fa == 0){
		cout << "NO";
	}
return 0;
}