# Program to find minimum possible sum by changing 0s to 1s k times from a list of numbers in Python?

PythonServer Side ProgrammingProgramming

Suppose we have a list of numbers called nums and another value k. We have to following operation k times: Select any number on the list. In the binary representation of that number, select a bit that is 0 and make it 1. Finally, we have to return the minimum possible sum of all the numbers after performing k operations. If the answer is too high, return result mode 10^9+7.

So, if the input is like nums = [4, 7, 3] k = 2, then the output will be 17, as the binary representation of 4 is 100, 3 is 011, and 7 is 111. Since we need to set 2 bits, we can set the bits of 4 to make it 111 (7). Then the total sum is then 7 + 7 + 3 = 17.

To solve this, we will follow these steps:

• ans := 0, i := 0

• while k is non-zero, do

• for each n in nums, do

• if (n / 2^i) is even, then

• ans := ans + 2^i

• k := k - 1

• if k is same as 0, then

• come out from the loop

• i := i + 1

• return (ans + sum of all elements of nums) mod m

Let us see the following implementation to get better understanding:

## Example

Live Demo

class Solution:
def solve(self, nums, k):
m = (10 ** 9 + 7)
ans = 0
i = 0
while k:
for n in nums:
if (n >> i) & 1 == 0:
ans += 1 << i
k -= 1
if k == 0:
break
i += 1
return (ans + sum(nums)) % m

ob = Solution()
nums = [4, 7, 3]
k = 2
print(ob.solve(nums, k))

## Input

[4, 7, 3], 2

## Output

17
Updated on 10-Nov-2020 07:55:14