Reshape The Matrix · Interview Problem

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Leetcode

Easy

Arrays

Matrices

Reshape The Matrix

Reshape a matrix into a new size while preserving the original row-major order of its elements.

Acceptance 0%

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Problem Statement

Problem

Given an $m \times n$ matrix, reshape it into a new matrix with dimensions $r \times c$ .

The reshaping must keep the elements in the same row-major order as the original matrix. If the reshape is not possible because the total number of elements does not match, return the original matrix unchanged.

Notes

Elements must be read left to right, top to bottom.
The new matrix should also be filled left to right, top to bottom.
If $m \times n \ne r \times c$ , no valid reshape exists.

Input Format

A 2D integer matrix mat
Two integers r and c representing the desired number of rows and columns

Output Format

Return the reshaped matrix if possible
Otherwise return the original matrix

Constraints

1 <= m, n <= 100
1 <= r, c <= 100
The matrix contains integers
The total number of elements may or may not match the requested shape

Examples

Sample cases returned by the problem API.

Example 1

Input

mat = [[1,2],[3,4]], r = 1, c = 4

Output

[[1,2,3,4]]

Explanation

The matrix has 4 elements, and $1 \times 4 = 4$ , so reshaping is valid. The row-major order is preserved.

Example 2

Input

mat = [[1,2],[3,4]], r = 2, c = 3

Output

[[1,2],[3,4]]

Explanation

The matrix has 4 elements, but $2 \times 3 = 6$ , so reshaping is impossible. Return the original matrix.

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