Integer Replacement
Given a positive integer n and you can do operations as follow:
If n is even, replace n with n/2.
If n is odd, you can replace n with either n + 1 or n - 1.
What is the minimum number of replacements needed for n to become 1?
Example 1:
Input:
8
Output:
3
Explanation:
8 -> 4 -> 2 -> 1
Example 2:
Input:
7
Output:
4
Explanation:
7 -> 8 -> 4 -> 2 -> 1
or
7 -> 6 -> 3 -> 2 -> 1
public class Solution {
public int integerReplacement(int n) {
if (n == Integer.MAX_VALUE) {
return 32;
}
int count = 0;
while (n > 1) {
if (n % 2 == 0) {
n = n / 2;
} else {
if ((n + 1) % 4 == 0 && n != 3) {
n++;
} else {
n--;
}
}
count++;
}
return count;
}
}
Hope this helps,
Michael