Files
snk/packages/solver/clearCleanColoredLayer.ts
2025-02-20 19:58:59 +07:00

131 lines
3.0 KiB
TypeScript

import {
getColor,
isEmpty,
isInside,
isInsideLarge,
setColorEmpty,
} from "@snk/types/grid";
import {
getHeadX,
getHeadY,
getSnakeLength,
nextSnake,
snakeEquals,
snakeWillSelfCollide,
} from "@snk/types/snake";
import { around4, Point } from "@snk/types/point";
import { getBestTunnel } from "./getBestTunnel";
import { fillOutside } from "./outside";
import type { Outside } from "./outside";
import type { Snake } from "@snk/types/snake";
import type { Color, Empty, Grid } from "@snk/types/grid";
export const clearCleanColoredLayer = (
grid: Grid,
outside: Outside,
snake0: Snake,
color: Color,
) => {
const snakeN = getSnakeLength(snake0);
const points = getTunnellablePoints(grid, outside, snakeN, color);
const chain: Snake[] = [snake0];
while (points.length) {
const path = getPathToNextPoint(grid, chain[0], color, points)!;
path.pop();
for (const snake of path)
setEmptySafe(grid, getHeadX(snake), getHeadY(snake));
chain.unshift(...path);
}
fillOutside(outside, grid);
chain.pop();
return chain;
};
type M = { snake: Snake; parent: M | null };
const unwrap = (m: M | null): Snake[] =>
!m ? [] : [m.snake, ...unwrap(m.parent)];
const getPathToNextPoint = (
grid: Grid,
snake0: Snake,
color: Color,
points: Point[],
) => {
const closeList: Snake[] = [];
const openList: M[] = [{ snake: snake0 } as any];
while (openList.length) {
const o = openList.shift()!;
const x = getHeadX(o.snake);
const y = getHeadY(o.snake);
const i = points.findIndex((p) => p.x === x && p.y === y);
if (i >= 0) {
points.splice(i, 1);
return unwrap(o);
}
for (const { x: dx, y: dy } of around4) {
if (
isInsideLarge(grid, 2, x + dx, y + dy) &&
!snakeWillSelfCollide(o.snake, dx, dy) &&
getColorSafe(grid, x + dx, y + dy) <= color
) {
const snake = nextSnake(o.snake, dx, dy);
if (!closeList.some((s0) => snakeEquals(s0, snake))) {
closeList.push(snake);
openList.push({ snake, parent: o });
}
}
}
}
};
/**
* get all cells that are tunnellable
*/
export const getTunnellablePoints = (
grid: Grid,
outside: Outside,
snakeN: number,
color: Color,
) => {
const points: Point[] = [];
for (let x = grid.width; x--; )
for (let y = grid.height; y--; ) {
const c = getColor(grid, x, y);
if (
!isEmpty(c) &&
c <= color &&
!points.some((p) => p.x === x && p.y === y)
) {
const tunnel = getBestTunnel(grid, outside, x, y, color, snakeN);
if (tunnel)
for (const p of tunnel)
if (!isEmptySafe(grid, p.x, p.y)) points.push(p);
}
}
return points;
};
const getColorSafe = (grid: Grid, x: number, y: number) =>
isInside(grid, x, y) ? getColor(grid, x, y) : (0 as Empty);
const setEmptySafe = (grid: Grid, x: number, y: number) => {
if (isInside(grid, x, y)) setColorEmpty(grid, x, y);
};
const isEmptySafe = (grid: Grid, x: number, y: number) =>
!isInside(grid, x, y) && isEmpty(getColor(grid, x, y));