Solve small, then widen

The AP style guide for humans: solve the smallest version of the problem first, then widen it.

Take: "Return true if every element of words has length at least k."

• Smallest case: an empty array. "Every element" of nothing is vacuously true — return true.
• One element: check words[0].length() >= k.
• All elements: loop, and the moment one fails, return false. Only after the loop finishes may you return true.

public static boolean allLong(String[] words, int k) {
    for (String w : words) {
        if (w.length() < k) {
            return false;
        }
    }
    return true;
}

Two habits this procedure builds:

1. The early-exit pattern. "Every / no / none" questions want you to return the moment the answer is decided, then give the default after the loop. Students who instead try to track a flag often initialize it wrong (true vs false) — decide the default from the vacuous case.
2. The negation test. "Every element has length ≥ k" fails exactly when some element has length < k — so the if tests the failure, not the success. Translating negations correctly is worth points on nearly every exam.

The same widening works for accumulation (sum → sum with condition → count of condition) and for searching (does it exist → where → first occurrence). Start where the problem is already solved; add complexity one obligation at a time.