Closest Prime Numbers in Range.java

class Solution {
    public int[] closestPrimes(int left, int right) {
        if (right < left) return new int[]{-1, -1};

        boolean[] isPrime = new boolean[right + 1];
        Arrays.fill(isPrime, true);
        isPrime[0] = isPrime[1] = false;

        for (int i = 2; i * i <= right; i++) {
            if (isPrime[i]) {
                for (int j = i * i; j <= right; j += i) {
                    isPrime[j] = false;
                }
            }
        }

        List<Integer> primes = new ArrayList<>();
        for (int i = left; i <= right; i++) {
            if (isPrime[i]) {
                primes.add(i);
            }
        }

        if (primes.size() < 2) return new int[]{-1, -1};

        int minDiff = Integer.MAX_VALUE;
        int first = -1, second = -1;

        for (int i = 1; i < primes.size(); i++) {
            int diff = primes.get(i) - primes.get(i - 1);
            if (diff < minDiff) {
                minDiff = diff;
                first = primes.get(i - 1);
                second = primes.get(i);
            }
        }

        return new int[]{first, second};
    }
}