n0054_spiral_matrix.rs

/**
 * [54] Spiral Matrix
 *
 * Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.
 * 
 * Example 1:
 * 
 * 
 * Input:
 * [
 *  [ 1, 2, 3 ],
 *  [ 4, 5, 6 ],
 *  [ 7, 8, 9 ]
 * ]
 * Output: [1,2,3,6,9,8,7,4,5]
 * 
 * 
 * Example 2:
 * 
 * Input:
 * [
 *   [1, 2, 3, 4],
 *   [5, 6, 7, 8],
 *   [9,10,11,12]
 * ]
 * Output: [1,2,3,4,8,12,11,10,9,5,6,7]
 * 
 */
pub struct Solution {}

// submission codes start here

impl Solution {
    pub fn spiral_order(matrix: Vec<Vec<i32>>) -> Vec<i32> {
        let mut res = Vec::new();
        if matrix.len() < 1 { return res }
        let (height, width) = (matrix.len(), matrix[0].len());
        let (mut x_min, mut x_max, mut y_min, mut y_max) = (0, height, 0, width);
        loop {
            for y in y_min..y_max { res.push(matrix[x_min][y]) }
            x_min += 1;
            if x_min == x_max { break }
            for x in x_min..x_max { res.push(matrix[x][y_max-1]) }
            y_max -= 1;
            if y_min == y_max { break }
            for y in (y_min..y_max).rev() { res.push(matrix[x_max-1][y]) }
            x_max -= 1;
            if x_min == x_max { break }
            for x in (x_min..x_max).rev() { res.push(matrix[x][y_min]) }
            y_min += 1;
            if y_min == y_max { break }
        }
        res
    }
}

// submission codes end

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_54() {
        assert_eq!(Solution::spiral_order(vec![
            vec![ 1, 2, 3 ],
            vec![ 4, 5, 6 ],
            vec![ 7, 8, 9 ]
        ]), vec![1,2,3,6,9,8,7,4,5]);
        assert_eq!(Solution::spiral_order(vec![
            vec![ 1, 2, 3 ]
        ]), vec![1,2,3]);
        assert_eq!(Solution::spiral_order(vec![
            vec![1],
            vec![2],
            vec![3],
        ]), vec![1,2,3]);
        assert_eq!(Solution::spiral_order(vec![
            vec![1],
        ]), vec![1]);
        assert_eq!(Solution::spiral_order(vec![
            vec![ 1, 2  ],
            vec![ 4, 5  ],
        ]), vec![1,2,5,4]);

    }
}