prathams's blog

Solving 2 equation
By prathams, history, 9 years ago, In English

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?

Tags xor
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9 years ago, hide # |
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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?

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9 years ago, hide # |
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Hint

By the way, I solved this question few months back and this is the code: https://ideone.com/WmTLgr

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9 years ago, hide # |
 
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Another way to solve this problem to simulate the process using digit DP, it works in O(logN).

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