Find the longest winning streak
A sequence of game results is recorded as wins and losses. Find the length of the longest unbroken streak of wins.
- A streak is a consecutive run of true values.
- A false value breaks any current streak.
- An empty list or all losses returns zero.
winStreak(results: list<bool>) → int
Java 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
int winStreak(List<Boolean> results) {
}Worked examples
| Call | Result |
|---|---|
winStreak(Main.<Boolean>ls(true, true, false, true)) | 2 |
winStreak(Main.<Boolean>ls(false, false, false)) | 0 |
winStreak(Main.<Boolean>ls(true, true, true)) | 3 |
winStreak(Main.<Boolean>ls()) | 0 |
Hint
Keep a running counter that resets on every false, and track the best so far.
Reference solution in Java
int winStreak(List<Boolean> results) {
int best = 0, cur = 0;
for (boolean r : results) {
if (r) { cur++; if (cur > best) best = cur; }
else cur = 0;
}
return best;
}