Reset tallies: Boss receipt
Inputs
readings is a list of integers (numbers with no decimal part). It may be empty, and numbers may repeat unless task 1 says otherwise.
Your tasks
- Create a list
tallies. Start a total at 0. Readreadingsfrom left to right. If the next number is 0, reset the total to 0. Otherwise, add that number to the total. Put the total intalliesafter each number. - Multiply each number in
talliesby its position, counting from 1: the first number by 1, the second by 2, and so on. - Add those products. Store the sum in
weightedTotal. - Complete
resetTalliesBossReceiptso it returnsweightedTotal. Return it, do not print it.
Example
If readings is [-9, 9, 5, 4, 9], then tallies is [-9, 0, 5, 9, 18] and resetTalliesBossReceipt returns 132.
Rules
- If
talliesis empty, return 0.
Test data
TEST DATA 1: readings is [19, 0, 14, 19, -9].
TEST DATA 2: readings is [5, 5, -3, 5].
Examples
Input: readings = [19,0,14,19,-9] Output: 313
tallies is [19, 0, 14, 33, 24]. Multiply by positions that start at 1: 1 * (19) + 2 * (0) + 3 * (14) + 4 * (33) + 5 * (24) = 313. Return 313.
Input: readings = [5,5,-3,5] Output: 94
tallies is [5, 10, 7, 12]. Multiply by positions that start at 1: 1 * (5) + 2 * (10) + 3 * (7) + 4 * (12) = 94. Return 94.
Input: readings = [] Output: 0
tallies is []. There are no numbers to multiply or add, so return 0.
Input limits
- 0 <= input size <= 64.
- Answers fit in a signed 32-bit integer: -2,147,483,648 through 2,147,483,647.
- Input numbers have no decimal part. They range from -1,000,000 to 1,000,000. Follow any extra input rules in task 1.
Efficiency goal
Big-O describes how the work or memory needed grows as the input gets larger.
Efficiency goal: time O(n); extra memory, including the helper list, O(n). n is the input length. These labels describe how work and memory grow with the input.
Practice focus
Build tallies first, then return exactly what the tasks ask for. Follow the order, keep repeated values when the rule says so, and check the empty case.