Given x and y, we need to find smallest a and b such that
a + b = x
a xor b = y
How to solve this?
→ Обратите внимание
→ Трансляции
→ Лидеры (рейтинг)
| № | Пользователь | Рейтинг |
|---|---|---|
| 1 | tourist | 4009 |
| 2 | jiangly | 3823 |
| 3 | Benq | 3738 |
| 4 | Radewoosh | 3633 |
| 5 | jqdai0815 | 3620 |
| 6 | orzdevinwang | 3529 |
| 7 | ecnerwala | 3446 |
| 8 | Um_nik | 3396 |
| 9 | ksun48 | 3390 |
| 10 | gamegame | 3386 |
| Страны | Города | Организации | Всё → |
→ Лидеры (вклад)
| № | Пользователь | Вклад |
|---|---|---|
| 1 | cry | 165 |
| 2 | maomao90 | 164 |
| 3 | Um_nik | 163 |
| 4 | atcoder_official | 160 |
| 4 | adamant | 160 |
| 6 | -is-this-fft- | 158 |
| 7 | awoo | 157 |
| 8 | TheScrasse | 154 |
| 8 | Dominater069 | 154 |
| 8 | nor | 154 |
→ Найти пользователя
→ Прямой эфир
Codeforces (c) Copyright 2010-2024 Михаил Мирзаянов
Соревнования по программированию 2.0
Время на сервере: 15.11.2024 11:43:10 (i1).
Десктопная версия, переключиться на мобильную.
При поддержке
Is it 1 ≤ x, y ≤ 107? If so, you can brute-force the value of a. If you decide the value of a, the value of b is determined to be x - a, and you can easily check a xor b.
But, I have two questions:
1. What is the actual constraints?
2. Smallest a and b? Which value should be minimized?
a + b can be written as (a^b) + (2 * (a&b)). So
x = y + 2 * (a&b) Which implies
a&b = (x - y) / 2.
Now can you find a, b such that their and is (x - y) / 2?
By the way, I solved this question few months back and this is the code: https://ideone.com/WmTLgr
Can you explained how we can write a + b as (a^b) + (2 * (a&b)) ?
Search for "add two numbers using bitwise operators". Also there is a similar problem in codeforces which you might be interested: http://codeforces.net/contest/635/problem/C
Another way to solve this problem to simulate the process using digit DP, it works in O(logN).
I guess constraints are x, y ≤ 1e18