ABC301 - D - Bitmask

0x00 Link

• D - Bitmask

• Source - AtCoder

• Tag - 芝士水题

• Time - $\ast$

0x01 Source Code

//
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
#define IOS ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

void solve() {
	string s;
	cin >> s;
	reverse(s.begin(), s.end());		//
	
	int n;
	cin >> n;
	
	int ans = 0;
	for (int i = s.size() - 1; i >= 0; i--) {
		ans |= (int)(s[i] == '1') << i; 				// LL
	}
	if (ans > n) {
		cout << -1 << endl;
		return ;
	}
	
	for (int i = s.size() - 1; i >= 0; i--) {
		if (s[i] == '?' && (ans | (1LL << i)) <= n) {	// 按位的优先级超级低 
			ans |= (1LL << i);							// 1LL
		}
	}
	cout << ans << endl;
}

signed main() {
	IOS
	int t = 1;
//	cin >> t;
	while (t--) solve();
	return 0;
} 

0x10 Diagram

• 404

0x11 Reference

• D - Bitmask Editorial by evima
• C语言运算符优先级表

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作者 | 乐意奥AI