/** A cell in a nonogram line: not yet determined, painted, or ruled out. */
export type NonogramCell = "unknown" | "filled" | "empty";
/** A line clue — the lengths of its consecutive filled runs, in order. */
export type NonogramClue = readonly number[];
/** A solved grid, row-major; `true` is a filled cell. */
export type NonogramSolution = readonly (readonly boolean[])[];
/** Run lengths of the filled cells in a boolean line — the clue a solved line yields.
 * @internal
 */
export declare function runLengths(line: readonly boolean[]): number[];
/** Row and column clues derived from a solution grid — the puzzle a solved board poses.
 * @internal
 */
export declare function deriveClues(solution: NonogramSolution): {
    rows: number[][];
    cols: number[][];
};
/**
 * Constraint-propagate one line against its `clue`: intersect every clue-consistent arrangement, forcing a
 * cell `filled` when it is filled in all of them and `empty` when empty in all, leaving the rest `unknown`.
 * Returns the tightened line, or `null` on contradiction (no arrangement fits the current cells) — the
 * per-line deduction step at the heart of every nonogram/picross solver.
  * @internal
  */
export declare function solveLine(line: readonly NonogramCell[], clue: NonogramClue): NonogramCell[] | null;
/** Outcome of {@link solveNonogram}: the deduced board and whether propagation fully determined it. */
export interface NonogramSolveResult {
    /** True when every cell is decided by line propagation alone (the puzzle is uniquely line-solvable). */
    solved: boolean;
    /** The board after propagation stalls — `unknown` cells remain when solving needs guessing. */
    board: NonogramCell[][];
}
/**
 * Solve a nonogram from its row and column clues by iterated line propagation until the board stops
 * changing. `solved` is true iff the board is fully determined without guessing — the standard test for
 * whether a nonogram is fair. Returns `solved: false` with a partial board on contradiction or ambiguity.
  * @internal
  */
export declare function solveNonogram(rows: readonly NonogramClue[], cols: readonly NonogramClue[]): NonogramSolveResult;