Suppose we have a list customers and another list mood, these two are of same length, we also have another integer k. Now on each minute i, customers[i] number of people come to the store and when mood[i] = 1, it indicates the customers are happy and when mood[i] = 0, then they are sad. We can set a sublist of size k of mood to 1s, finally we have to find the maximum number of people we can make happy.
So, if the input is like customers = [2, 3, 6, 6, 3] mood = [1, 1, 0, 0, 0] k = 2, then the output will be 17 because if we set mood[2] and mood[3] to 1, then the total mood will be 2 + 3 + 6 + 6 = 17 customers happy.
To solve this, we will follow these steps −
- n := size of mood
- a := a list of size (n + 1) and fill with 0
- s := 0
- for i in range 0 to n - 1, do
- a[i + 1] := a[i]
- if mood[i] is non-zero, then
- s := s + customers[i]
- otherwise,
- a[i + 1] := a[i + 1] + customers[i]
- d := 0
- for i in range k to n, do
- d := maximum of d and (a[i] - a[i - k])
- return s + d
Example
Let us see the following implementation to get better understanding −
def solve(customers, mood, k): n = len(mood) a = [0] * (n + 1) s = 0 for i in range(n): a[i + 1] = a[i] if mood[i]: s += customers[i] else: a[i + 1] += customers[i] d = 0 for i in range(k, n + 1): d = max(d, a[i] - a[i - k]) return s + d customers = [2, 3, 6, 6, 3] mood = [1, 1, 0, 0, 0] k = 2 print(solve(customers, mood, k))
Input
[2, 3, 6, 6, 3], [1, 1, 0, 0, 0], 2
Output
17