spiral matrix

spiral_matrix_vector_direction.js

var beetwen = function(point, bords){
    let [x, y] = point
    let [xmin, ymin, xmax, ymax] = bords
    return xmin < x && x < xmax && ymin < y && y < ymax
} 

/**
 * @param {number[][]} matrix
 * @return {number[]}
 */
var spiralOrder = function(matrix, direction, start, rect) {
    if (matrix.length == 0)
        return []
    let s = matrix.length * matrix[0].length
    direction = direction ? direction : [1, 0]
    start = start ? start : [0, 0]
    rect = rect ? rect : [-1, -1, matrix[0].length, matrix.length]
    let result = []
    while(beetwen(start, rect)){
        let [x, y] = start
        result.push(matrix[y][x])
        // let's go toward direction
        start[0] = start[0] + direction[0]
        start[1] = start[1] + direction[1]
    }
    
    // stop recursion if it was center
    if (result.length == 0)
        return result
    
    // now we out of bounds
    // go back by one step
    start[0] = start[0] - direction[0]
    start[1] = start[1] - direction[1]
    
    // now we need to rotate direction on 90 degrees
    let [xD, yD] = direction
    direction = [-yD , xD]
    
    // we need to reduce our bounds in this derection
    
    // change borders for x
    rect[0] = direction[0] > 0 ? rect[0] + 1 : rect[0]
    rect[2] = direction[0] < 0 ? rect[2] - 1 : rect[2]
    
    // change borders for y
    rect[1] = direction[1] > 0 ? rect[1] + 1 : rect[1]
    rect[3] = direction[1] < 0 ? rect[3] - 1 : rect[3]
    
    // next start position should be on next side
    start[0] = start[0] + direction[0]
    start[1] = start[1] + direction[1]
    
    // concatinate with child results
    return result.concat(spiralOrder(matrix, direction, start, rect))
};