Day 48.2.txt

991. Broken Calculator

There is a broken calculator that has the integer startValue on its display initially. In on operation you can:

multiply the number on the display by 2, or
subtract 1 from the number on the display.
Given two integers startValue and target, return the minimum number of operations needed to display target on the calculator.

 

Example 1:

Input: startValue = 2, target = 3
Output: 2
Explanation: Use double operation and then decrement operation {2 -> 4 -> 3}.
Example 2:

Input: startValue = 5, target = 8
Output: 2
Explanation: Use decrement and then double {5 -> 4 -> 8}.
Example 3:

Input: startValue = 3, target = 10
Output: 3
Explanation: Use double, decrement and double {3 -> 6 -> 5 -> 10}.
Example 4:

Input: startValue = 1024, target = 1
Output: 1023
Explanation: Use decrement operations 1023 times.

Constraints:

1 <= x, y <= 109




class Solution {
    public int brokenCalc(int s, int t) {
        int c=0;
        while(t>s)
        {
            c++;
            if(t%2==0)
                t/=2;
            else
                t++;
        }
        return c+(s-t);
    }
}