app/src/main/java/sudoku/Solver.java
public boolean isUniqueArray(int[] a) {
        Set<Integer> collect = new HashSet<Integer>();
        for (int n : a) {
            if (n != 0 && collect.contains(n)) return false;
            collect.add(n);
        }
        return true;
    }
/**
     * Returns true if a contains one of less of each number in [1, getDimension()], else false.
     * 
     * @param a
     *        the array to check
     * @return true if array is unique, false otherwise
     */
Returns true if a contains one of less of each number in [1, getDimension()], else false.

@param a
the array to check
@return true if array is unique, false otherwise
Returns true if a contains one of less of each number in [ 1 getDimension () ] else false . @param a the array to check @return true if array is unique false otherwise
public boolean isUniqueArray(int[] a) {
        Set<Integer> collect = new HashSet<Integer>();
        for (int n : a) {
            if (n != 0 && collect.contains(n)) return false;
            collect.add(n);
        }
        return true;
    }
public boolean isUniqueArray ( int [ ] a ) { Set < Integer > collect = new HashSet < Integer > ( ) ; for ( int n : a ) { if ( n != 0 && collect . contains ( n ) ) return false ; collect . add ( n ) ; } return true ; }
Returns true if a contains one of less of each number in [1, getDimension()], else false.
Returns true if a contains one of less of each number in [ 1 getDimension () ] else false .