import { CellCollection } from './CellCollection';
import { CellValueChange } from './Grid';
/**
 * Implements a class that holds various strategies for solving puzzles.
 */
export declare class SolverStrategies {
    /**
     * Pivots the cell values into an object that provides the frequency and locations
     * of values in the specified row, column or block.
     * @param block A reference to a Grid Row, Column or Block.
     * @returns A reference to a ReducedValues object that shows value frequency.
     */
    private static reduceCells;
    /**
     * Searches a given Row, Column or Block for cells where its potentials have collapsed into a
     * single value. It then returns an array of objects to remove the potential to other
     * cells in the block.
     * @param block A reference to a row, column or block that holds 9 unique values.
     * @returns An array of changes that can be applied back to the grid.
     */
    static findCollapsedValues(block: CellCollection): CellValueChange[];
    /**
     * Searches a given Row, Column or Block for cells where its value doesn't appear
     * in any of the other cells implying that it should have that value.
     * @param block A reference to a row, column or block that holds 9 unique values.
     * @returns An array of changes that can be applied back to the grid.
     */
    static findSingleValues(block: CellCollection): CellValueChange[];
    /**
     * Searches a given row, column or block for hiddden pairs and returns an
     * array of objects to remove unneeded potentials in those pairs.
     * @param block A reference to a row, column or block to process.
     * @returns An array of GridDifference objects to apply back to the Grid.
     */
    static findHiddenPairs(block: CellCollection): CellValueChange[];
    /**
     * Searches a given row, column or block for obvious pairs and returns an
     * array of objects to remove unneeded potentials from the rest of the cells.
     * @param block A reference to a row, column or block to process.
     * @returns An array of GridDifference objects to apply back to the Grid.
     */
    static findObviousPairs(block: CellCollection): CellValueChange[];
}