Check if There is a Valid Path in a Grid LeetCode solution in JavaScript

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// Memory Usage: 50.9 MB, less than 100.00%
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var hasValidPath = function (grid) {
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  if (grid[0][0] === 5) return false;
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  const M = grid.length,
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    N = grid[0].length;
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  const SEGMENTS = {
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    1: {
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      dirs: [
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        [0, -1],
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        [0, 1],
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      ],
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      adjs: [
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        [1, 4, 6],
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        [1, 3, 5],
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      ],
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    },
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    2: {
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      dirs: [
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        [-1, 0],
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        [1, 0],
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      ],
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      adjs: [
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        [2, 3, 4],
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        [2, 5, 6],
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      ],
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    },
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    3: {
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      dirs: [
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        [0, -1],
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        [1, 0],
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      ],
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      adjs: [
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        [1, 4, 6],
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        [2, 5, 6],
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      ],
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    },
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    4: {
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      dirs: [
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        [0, 1],
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        [1, 0],
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      ],
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      adjs: [
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        [1, 3, 5],
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        [2, 5, 6],
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      ],
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    },
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    5: {
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      dirs: [
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        [-1, 0],
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        [0, -1],
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      ],
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      adjs: [
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        [2, 3, 4],
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        [1, 4, 6],
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      ],
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    },
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    6: {
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      dirs: [
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        [-1, 0],
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        [0, 1],
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      ],
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      adjs: [
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        [2, 3, 4],
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        [1, 3, 5],
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      ],
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    },
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  };
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  let path = Array.from(
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    { length: grid.length },
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    (el) => new Uint16Array(grid[0].length)
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  );
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  let y = 0,
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    x = 0;
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  function getNextSegment(segment, y, x) {
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    let dir = 0;
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    let ny = y + SEGMENTS[segment].dirs[dir][0];
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    let nx = x + SEGMENTS[segment].dirs[dir][1];
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    if (ny < 0 || ny >= M || nx < 0 || nx >= N || path[ny][nx]) {
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      dir = 1;
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      ny = y + SEGMENTS[segment].dirs[dir][0];
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      nx = x + SEGMENTS[segment].dirs[dir][1];
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    }
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    return { dir, ny, nx };
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  }
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  function isValid(y, x) {
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    for (let i = 0; i < M * N; i++) {
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      if (y == M - 1 && x == N - 1) return true;
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      path[y][x] = i + 1;
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      let cur = grid[y][x];
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      let next = getNextSegment(cur, y, x);
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      if (next.ny >= M || next.nx >= N) return false;
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      if (!SEGMENTS[cur].adjs[next.dir].includes(grid[next.ny][next.nx]))
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        return false;
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      y = next.ny;
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      x = next.nx;
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    }
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    return false;
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  }
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  if (grid[0][0] !== 4) return isValid(y, x);
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  path[0][0] = 1;
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  return isValid(y, x + 1) || isValid(y + 1, x);
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};