Leetcode accepted

PriyankaKhire · PriyankaKhire · commit 501bdaf13ea0 · 2021-08-22T22:57:20.000-07:00
diff --git a/Blind 75/Programs/Rotate Image.py b/Blind 75/Programs/Rotate Image.py
@@ -0,0 +1,31 @@
+# Rotate Image
+# https://leetcode.com/problems/rotate-image/
+
+class Solution(object):
+    def diagonalSwap(self, matrix):
+        colBound = 0
+        rowBound = 0
+        # extra minus one is from preventing the diagonal getting swapped
+        while(rowBound < len(matrix)-1):
+            # swap cells, we wanna swap row, col with len-1-col, len-1-row
+            matrix[rowBound][colBound], matrix[len(matrix[0])-1-colBound][len(matrix)-1-rowBound] = matrix[len(matrix[0])-1-colBound][len(matrix)-1-rowBound], matrix[rowBound][colBound]
+            # increment the col value
+            colBound = colBound + 1
+            # extra minus row bound is from preventing the diagonal from getting swapped.
+            if (colBound == len(matrix[0])-1-rowBound):
+                colBound = 0
+                rowBound = rowBound + 1
+    
+    def inverseMatrix(self, matrix):
+        for row in range(len(matrix)/2):
+            # swap first row with last
+            matrix[row], matrix[len(matrix)-1-row] = matrix[len(matrix)-1-row], matrix[row]
+                
+    def rotate(self, matrix):
+        self.diagonalSwap(matrix)
+        self.inverseMatrix(matrix)
+        """
+        :type matrix: List[List[int]]
+        :rtype: None Do not return anything, modify matrix in-place instead.
+        """
+        
diff --git a/Blind 75/README.md b/Blind 75/README.md
@@ -1,6 +1,6 @@
 <h1>Blind 75</h1>
   <a href="https://leetcode.com/discuss/general-discussion/460599/blind-75-leetcode-questions">Leetcode link to the post.</a>
-  <h4>Total Completed: 27</h4>
+  <h4>Total Completed: 28</h4>
   <h2>Array</h2>
     <ul>
       <li><a href="Programs/Two Sum.py">Two Sum</a> 
@@ -207,7 +207,12 @@
           Don't forget the mark the cells visited to avoid duplicates.
         </p>
       </li>
-      <li>Rotate Image</li>
+      <li><a href="Programs/Rotate Image.py">Rotate Image</a> 
+        <p><b>Approach</b>: First swap the elements under red triangle with the green triangle.<br/>
+          <img src="img/Diagonal-Swap.png" height="200" width="200"><br/>
+          Then flip the matrix upside down.
+        </p>
+      </li>
       <li>Word Search</li>
     </ul>
   <h2>String</h2>
diff --git a/Blind 75/img/Diagonal-Swap.png b/Blind 75/img/Diagonal-Swap.png
