Package g2201_2300.s2220_minimum_bit_flips_to_convert_number

Class Solution

java.lang.Object

g2201_2300.s2220_minimum_bit_flips_to_convert_number.Solution

public class Solution
extends Object

2220 - Minimum Bit Flips to Convert Number.<p>Easy</p> <p>A <strong>bit flip</strong> of a number <code>x</code> is choosing a bit in the binary representation of <code>x</code> and <strong>flipping</strong> it from either <code>0</code> to <code>1</code> or <code>1</code> to <code>0</code>.</p> <ul> <li>For example, for <code>x = 7</code>, the binary representation is <code>111</code> and we may choose any bit (including any leading zeros not shown) and flip it. We can flip the first bit from the right to get <code>110</code>, flip the second bit from the right to get <code>101</code>, flip the fifth bit from the right (a leading zero) to get <code>10111</code>, etc.</li> </ul> <p>Given two integers <code>start</code> and <code>goal</code>, return <em>the <strong>minimum</strong> number of <strong>bit flips</strong> to convert</em> <code>start</code> <em>to</em> <code>goal</code>.</p> <p><strong>Example 1:</strong></p> <p><strong>Input:</strong> start = 10, goal = 7</p> <p><strong>Output:</strong> 3</p> <p><strong>Explanation:</strong> The binary representation of 10 and 7 are 1010 and 0111 respectively. We can convert 10 to 7 in 3 steps:</p> <ul> <li> <p>Flip the first bit from the right: 1010 -> 1011.</p> </li> <li> <p>Flip the third bit from the right: 1011 -> 1111.</p> </li> <li> <p>Flip the fourth bit from the right: 1111 -> 0111.</p> </li> </ul> <p>It can be shown we cannot convert 10 to 7 in less than 3 steps. Hence, we return 3.</p> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> start = 3, goal = 4</p> <p><strong>Output:</strong> 3</p> <p><strong>Explanation:</strong> The binary representation of 3 and 4 are 011 and 100 respectively. We can convert 3 to 4 in 3 steps:</p> <ul> <li> <p>Flip the first bit from the right: 011 -> 010.</p> </li> <li> <p>Flip the second bit from the right: 010 -> 000.</p> </li> <li> <p>Flip the third bit from the right: 000 -> 100.</p> </li> </ul> <p>It can be shown we cannot convert 3 to 4 in less than 3 steps. Hence, we return 3.</p> <p><strong>Constraints:</strong></p> <ul> <li><code>0 <= start, goal <= 10⁹</code></li> </ul>

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	minBitFlips(int start, int goal)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Solution

public Solution()

Method Details

minBitFlips

public int minBitFlips(int start,
 int goal)