freecodecamp--freecodecamp/curriculum/challenges/english/blocks/daily-coding-challenges-javascript/698a1a73ade5ac0e19180fa4.md

id, title, challengeType, dashedName

id	title	challengeType	dashedName
698a1a73ade5ac0e19180fa4	Challenge 201: Matrix Shift	28	challenge-201

--description--

Given a matrix (array of arrays) of numbers and an integer, shift all values in the matrix by the given amount.

• A positive shift moves values to the right.
• A negative shift moves values to the left.

Values should wrap:

• Treat the matrix as one continuous sequence of values.
• When a value moves past the end of a row, it continues at the beginning of the next row.
• When a value moves past the last position in the matrix, it wraps to the first position.
• The same applies in reverse when shifting left.

For example, given:

[
  [1, 2, 3],
  [4, 5, 6]
]

with a shift of 1, move all the numbers to the right one:

[
  [6, 1, 2],
  [3, 4, 5]
]

--hints--

shiftMatrix([[1, 2, 3], [4, 5, 6]], 1) should return [[6, 1, 2], [3, 4, 5]].

assert.deepEqual(shiftMatrix([[1, 2, 3], [4, 5, 6]], 1), [[6, 1, 2], [3, 4, 5]]);

shiftMatrix([[1, 2, 3], [4, 5, 6]], -1) should return [[2, 3, 4], [5, 6, 1]].

assert.deepEqual(shiftMatrix([[1, 2, 3], [4, 5, 6]], -1), [[2, 3, 4], [5, 6, 1]]);

shiftMatrix([[1, 2, 3], [4, 5, 6], [7, 8, 9]], 5) should return [[5, 6, 7], [8, 9, 1], [2, 3, 4]].

assert.deepEqual(shiftMatrix([[1, 2, 3], [4, 5, 6], [7, 8, 9]], 5), [[5, 6, 7], [8, 9, 1], [2, 3, 4]]);

shiftMatrix([[1, 2, 3], [4, 5, 6], [7, 8, 9]], -6) should return [[7, 8, 9], [1, 2, 3], [4, 5, 6]].

assert.deepEqual(shiftMatrix([[1, 2, 3], [4, 5, 6], [7, 8, 9]], -6), [[7, 8, 9], [1, 2, 3], [4, 5, 6]]);

shiftMatrix([[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12], [13, 14, 15, 16]], 7) should return [[10, 11, 12, 13], [14, 15, 16, 1], [2, 3, 4, 5], [6, 7, 8, 9]].

assert.deepEqual(shiftMatrix([[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12], [13, 14, 15, 16]], 7), [[10, 11, 12, 13], [14, 15, 16, 1], [2, 3, 4, 5], [6, 7, 8, 9]]);

shiftMatrix([[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12], [13, 14, 15, 16]], -54) should return [[7, 8, 9, 10], [11, 12, 13, 14], [15, 16, 1, 2], [3, 4, 5, 6]].

assert.deepEqual(shiftMatrix([[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12], [13, 14, 15, 16]], -54), [[7, 8, 9, 10], [11, 12, 13, 14], [15, 16, 1, 2], [3, 4, 5, 6]]);

--seed--

--seed-contents--

function shiftMatrix(matrix, shift) {

  return matrix;
}

--solutions--

function shiftMatrix(matrix, shift) {
  const rows = matrix.length;
  const cols = matrix[0].length;
  const flat = matrix.flat();
  const n = flat.length;
  const s = ((shift % n) + n) % n;
  const shifted = flat.slice(-s).concat(flat.slice(0, n - s));
  const result = [];
  for (let i = 0; i < rows; i++) {
    result.push(shifted.slice(i * cols, (i + 1) * cols));
  }

  return result;
}