Method exch

src/test/resources/cha/MaxPQ.java:143–147

(int i, int j)

    }

    private void exch(int i, int j) {
        int swap = pq[i];
        pq[i] = pq[j];
        pq[j] = swap;
    }

    // is pq[1..n] a max heap?
    private boolean isMaxHeap() {