Code style fixes for matrix rotation algorithm.

Author: trekhleb

src/algorithms/uncategorized/square-matrix-rotation/README.md

@@ -92,13 +92,13 @@ A B C
 / / •
 / • •  
 
-And not let's do horizontal reflection:
+And now let's do horizontal reflection:
 
 A → →
 B → →
 C → →
 
-The string has been rotated to 90 degree.
+The string has been rotated to 90 degree:
 
 • • A
 • • B

src/algorithms/uncategorized/square-matrix-rotation/squareMatrixRotation.js

@@ -8,19 +8,28 @@ export default function squareMatrixRotation(originalMatrix) {
   // Do top-right/bottom-left diagonal reflection of the matrix.
   for (let rowIndex = 0; rowIndex < matrix.length; rowIndex += 1) {
     for (let columnIndex = rowIndex + 1; columnIndex < matrix.length; columnIndex += 1) {
-      const tmp = matrix[columnIndex][rowIndex];
-      matrix[columnIndex][rowIndex] = matrix[rowIndex][columnIndex];
-      matrix[rowIndex][columnIndex] = tmp;
+      // Swap elements.
+      [
+        matrix[columnIndex][rowIndex],
+        matrix[rowIndex][columnIndex],
+      ] = [
+        matrix[rowIndex][columnIndex],
+        matrix[columnIndex][rowIndex],
+      ];
     }
   }
 
   // Do horizontal reflection of the matrix.
   for (let rowIndex = 0; rowIndex < matrix.length; rowIndex += 1) {
     for (let columnIndex = 0; columnIndex < matrix.length / 2; columnIndex += 1) {
-      const mirrorColumnIndex = matrix.length - columnIndex - 1;
-      const tmp = matrix[rowIndex][mirrorColumnIndex];
-      matrix[rowIndex][mirrorColumnIndex] = matrix[rowIndex][columnIndex];
-      matrix[rowIndex][columnIndex] = tmp;
+      // Swap elements.
+      [
+        matrix[rowIndex][matrix.length - columnIndex - 1],
+        matrix[rowIndex][columnIndex],
+      ] = [
+        matrix[rowIndex][columnIndex],
+        matrix[rowIndex][matrix.length - columnIndex - 1],
+      ];
     }
   }