1260. Shift 2D Grid

Given a 2D grid of size m x n and an integer k. You need to shift the grid k times.

In one shift operation:

  • Element at grid[i][j] moves to grid[i][j + 1].
  • Element at grid[i][n - 1] moves to grid[i + 1][0].
  • Element at grid[m - 1][n - 1] moves to grid[0][0].

Return the 2D grid after applying shift operation k times.

 

Example 1:

Input: grid = [[1,2,3],[4,5,6],[7,8,9]], k = 1
Output: [[9,1,2],[3,4,5],[6,7,8]]

Example 2:

Input: grid = [[3,8,1,9],[19,7,2,5],[4,6,11,10],[12,0,21,13]], k = 4
Output: [[12,0,21,13],[3,8,1,9],[19,7,2,5],[4,6,11,10]]

Example 3:

Input: grid = [[1,2,3],[4,5,6],[7,8,9]], k = 9
Output: [[1,2,3],[4,5,6],[7,8,9]]

 

Constraints:

  • m == grid.length
  • n == grid[i].length
  • 1 <= m <= 50
  • 1 <= n <= 50
  • -1000 <= grid[i][j] <= 1000
  • 0 <= k <= 100

Rust Solution

struct Solution;

impl Solution {
    fn shift_grid(mut grid: Vec<Vec<i32>>, k: i32) -> Vec<Vec<i32>> {
        let n = grid.len();
        let m = grid[0].len();
        let mut a = vec![];
        for i in 0..n {
            for j in 0..m {
                a.push(grid[i][j]);
            }
        }
        let s = n * m;
        let mut k = s - (k as usize) % s;
        for i in 0..n {
            for j in 0..m {
                grid[i][j] = a[k % s];
                k += 1;
            }
        }
        grid
    }
}

#[test]
fn test() {
    let grid = vec_vec_i32![[1, 2, 3], [4, 5, 6], [7, 8, 9]];
    let k = 1;
    let res: Vec<Vec<i32>> = vec_vec_i32![[9, 1, 2], [3, 4, 5], [6, 7, 8]];
    assert_eq!(Solution::shift_grid(grid, k), res);
    let grid = vec_vec_i32![[3, 8, 1, 9], [19, 7, 2, 5], [4, 6, 11, 10], [12, 0, 21, 13]];
    let k = 4;
    let res: Vec<Vec<i32>> =
        vec_vec_i32![[12, 0, 21, 13], [3, 8, 1, 9], [19, 7, 2, 5], [4, 6, 11, 10]];
    assert_eq!(Solution::shift_grid(grid, k), res);
}

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