Method Percolation

01Lab-Percolation/Percolation.java:21–30

(int n)

    // creates n-by-n grid, with all sites initially blocked
    public Percolation(int n) {
        if (n <= 0) throw new IllegalArgumentException("n should be larger than 0");
        gridSize = n;
        uf1 = new WeightedQuickUnionUF(n * n + 1);
        uf2 = new WeightedQuickUnionUF(n * n + 2);
        sites = new boolean[n * n + 2];
        sites[0] = true; // uf1's top and uf2's top
        sites[n * n + 1] = true; // uf2's bottom
        numOfOpenSites = 0;
    }

    // calculate index for row col
    private int getSite(int row, int col) {