Reshape the Matrix – LeetCode Solution Java , Python 3, Python 2 , C , C++, Best and Optimal Solutions , All you need.

In MATLAB, there is a handy function called reshape which can reshape an m x n matrix into a new one with a different size r x c keeping its original data.

You are given an m x n matrix mat and two integers r and c representing the number of rows and the number of columns of the wanted reshaped matrix.

The reshaped matrix should be filled with all the elements of the original matrix in the same row-traversing order as they were.

If the reshape operation with given parameters is possible and legal, output the new reshaped matrix; Otherwise, output the original matrix.

Example 1:

Input: mat = [[1,2],[3,4]], r = 1, c = 4
Output: [[1,2,3,4]]

Example 2:

Input: mat = [[1,2],[3,4]], r = 2, c = 4
Output: [[1,2],[3,4]]

Constraints:

• m == mat.length
• n == mat[i].length
• 1 <= m, n <= 100
• -1000 <= mat[i][j] <= 1000
• 1 <= r, c <= 300

C++ Reshape the Matrix LeetCode Solution

class Solution {
public:
    vector<vector<int>> matrixReshape(vector<vector<int>>& mat, int r, int c) {
        int m = size(mat), n = size(mat[0]), total = m * n;
        if(r * c != total) return mat;   
        vector<vector<int>> ans(r, vector<int>(c));
        for(int col = 0; col < n; col++) {
            for(int row = 0; row < m; row++) {
                int new_row = (n * row + col) / c;
                int new_col = (n * row + col) % c;
                ans[new_row][new_col] = mat[row][col];                
            }
        }
        return ans;
    }
};

Java Reshape the Matrix LeetCode Solution

public int[][] matrixReshape(int[][] nums, int r, int c) {
    int n = nums.length, m = nums[0].length;
    if (r*c != n*m) return nums;
    int[][] res = new int[r][c];
    for (int i=0;i<r*c;i++) 
        res[i/c][i%c] = nums[i/m][i%m];
    return res;
}
 

Python 3 Reshape the Matrix LeetCode Solution

def matrixReshape(self, nums, r, c):
    if r * c != len(nums) * len(nums[0]):
        return nums
    it = itertools.chain(*nums)
    return [list(itertools.islice(it, c)) for _ in xrange(r)]

Array-1180
String-562
Hash Table-412
Dynamic Programming-390
Math-368
Sorting-264

Greedy-257
Depth-First Search-256
Database-215
Breadth-First Search-200
Tree-195

Binary Search-191
Matrix-176
Binary Tree-160
Two Pointers-151
Bit Manipulation-140

Stack-133
Heap (Priority Queue)-117
Design-116
Graph-108
Simulation-103
Prefix Sum-96

Backtracking-92
Counting-86
Sliding Window-73
Linked List-69
Union Find-66

Ordered Set-48
Monotonic Stack-47
Recursion-43
Trie-41
Binary Search Tree-40
Divide and Conquer-40

Enumeration-39
Bitmask-37
Queue-33
Memoization-32
Topological Sort-31

Geometry-30
Segment Tree-27
Game Theory-24
Hash Function-24
Binary Indexed Tree-21

Interactive-18
Data Stream-17
String Matching-17
Rolling Hash-17
Shortest Path-16

Number Theory-16
Combinatorics-15
Randomized-12
Monotonic Queue-9
Iterator-9
Merge Sort-9

Concurrency-9
Doubly-Linked List-8
Brainteaser-8
Probability and Statistics-7
Quickselect-7

Bucket Sort-6
Suffix Array-6
Minimum Spanning Tree-5
Counting Sort-5
Shell-4

Line Sweep-4
Reservoir Sampling-4
Eulerian Circuit-3
Radix Sort-3

Strongly Connected Componen-t2
Rejection Sampling-2
Biconnected Component-1

Leave a comment below

Related posts:

Spiral Matrix – LeetCode Solution Spiral Matrix II – LeetCode Solution Search a 2D Matrix – LeetCode Solution Set Matrix Zeroes – LeetCode Solution Search a 2D Matrix II – LeetCode Solution Longest Increasing Path in a Matrix – LeetCode Solution