Consecutive Runs

A run is a maximal sequence of consecutive elements that share a property — equal values, all positive, all even. Run-detection problems track a current streak and a best-so-far maximum.

Two counters do all the work: run grows when the condition continues; best records the longest run seen.

On the AP exam, run problems test loop discipline — reset on break, update best inside the match branch, start counter at 1.

Longest equal-run

public int longestEqualRun(int[] arr) {
    if (arr.length == 0) return 0;
    int best = 1;
    int run = 1;
    for (int i = 1; i < arr.length; i++) {
        if (arr[i] == arr[i - 1]) {
            run++;
            if (run > best) best = run;
        } else {
            run = 1;
        }
    }
    return best;
}

Run by condition (e.g., positive)

int run = 0, best = 0;
for (int n : arr) {
    if (n > 0) {
        run++;
        if (run > best) best = run;
    } else {
        run = 0;
    }
}

Different reset value: 0 because the condition can fail at the very first element.