added Reshape the Matrix (easy)

Author: minhyeong-joe

Easy/ReshapeMatrix/README.md

@@ -0,0 +1,44 @@
+
+# Reshape the Matrix
+[Leetcode Link](https://leetcode.com/problems/reshape-the-matrix/)
+
+## Problem:
+
+In MATLAB, there is a very useful function called 'reshape', which can reshape a matrix into a new one with different size but keep its original data.
+
+You're given a matrix represented by a two-dimensional array, and two **positive** integers **r** and **c** representing the **row** number and **column** number of the wanted reshaped matrix, respectively.
+
+The reshaped matrix need to 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:
+
+```
+Input: 
+nums = 
+[[1,2],
+ [3,4]]
+r = 1, c = 4
+Output: 
+[[1,2,3,4]]
+Explanation:
+The row-traversing of nums is [1,2,3,4]. The new reshaped matrix is a 1 * 4 matrix, fill it row by row by using the previous list.
+```
+```
+Input: 
+nums = 
+[[1,2],
+ [3,4]]
+r = 2, c = 4
+Output: 
+[[1,2],
+ [3,4]]
+Explanation:
+There is no way to reshape a 2 * 2 matrix to a 2 * 4 matrix. So output the original matrix.
+```
+
+## Note:
+
+1. The height and width of the given matrix is in range [1, 100].
+2. The given r and c are all positive.

Easy/ReshapeMatrix/solution.py

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+from typing import List
+
+
+def matrixReshape(nums: List[List[int]], r: int, c: int) -> List[List[int]]:
+ # if r and c not valid, return original list
+ if len(nums)*len(nums[0]) != r*c:
+ return nums
+ numCol = c
+ reshaped = list()
+ col = list()
+ # iterate over nums and decrement numCol by 1 and when numCol reaches 0, append that col list to reshaped list, and reset numCol to c
+ for i in range(len(nums)):
+ for j in range(len(nums[i])):
+ col.append(nums[i][j])
+ numCol -= 1
+ if numCol == 0:
+ # reset col list for next row
+ reshaped.append(col)
+ col = list()
+ numCol = c
+ return reshaped
+
+
+# test driver
+nums = [[1, 2, 3], [4, 5, 6]]
+r = 3
+c = 2
+print("Input: nums =", nums)
+print("r =", r, ", c =", c)
+print("Output:", matrixReshape(nums, r, c))

README.md

@@ -26,6 +26,7 @@ Languages used: Java and Python
  - [Maximize Sum Of Array After K Negations](Easy/MaximizeSumAfterKNegations)
  - [House Robber](Easy/HouseRobber)
  - [Majority Element](Easy/MajorityElement)
+ - [Reshape the Matrix](Easy/ReshapeMatrix)
 - Medium
  - [Minimum Add to Make Parentheses Valid](Medium/MinimumAddtoMakeParenthesesValid)
  - [Distribute Coins in Binary Tree](Medium/DistributionCoinsInBinaryTree)