Count the working days in a span
An SLA clock only runs on working days, so a span of calendar days has to be reduced to the ones that count.
- Weekdays are numbered 0 for Monday through 6 for Sunday.
- Saturday and Sunday do not count.
- The span starts on the given weekday and runs for that many consecutive days.
- A span of zero or less, or a weekday outside 0 to 6, counts nothing.
BusinessDays(startWeekday: int, spanDays: int) → int
C# needs a compiler and Drill does not host one yet, so this page is the reference rather than an exercise: the problem, worked examples, and the solution in full. To type it out, the same problem runs in Python.
Where you start
public int BusinessDays(int startWeekday, int spanDays) {
}Worked examples
| Call | Result |
|---|---|
BusinessDays(0, 7) | 5 |
BusinessDays(0, 5) | 5 |
BusinessDays(5, 2) | 0 |
BusinessDays(4, 4) | 2 |
Hint
Walk the days and take the weekday modulo 7, or work out the whole weeks first and handle the remainder.
Reference solution in C#
public int BusinessDays(int startWeekday, int spanDays) {
if (spanDays <= 0 || startWeekday < 0 || startWeekday > 6) return 0;
int n = 0;
for (int i = 0; i < spanDays; i++) if ((startWeekday + i) % 7 < 5) n++;
return n;
}