Merge pull request #28 from rroque98/rotateMatrix

Add JavaScript solution to 1.7 Rotate Matrix

Author: fvntr

JavaScript/chapter01/1.7 - Rotate Matrix/rroque98_sol.js

@@ -0,0 +1,29 @@
+/*Given an image represented by an N*N matrix where
+each pixel in the image is 4 bytes, write a method
+to rotate the image by 90 degrees. Can you do this
+in place?*/
+
+const rotateImage = nestedArr => {
+  const n = nestedArr.length;
+  if (n === 0 || n === 1) {
+    return nestedArr;
+  }
+  var rotatedArr = [];
+  for (let col = 0; col < n; col++) {
+    let newRow = [];
+    for (let row = n - 1; row >= 0; row--) {
+      newRow.push(nestedArr[row][col]);
+    }
+    rotatedArr.push(newRow);
+  }
+  return rotatedArr;
+};
+
+// TESTS:
+console.log(
+  JSON.stringify(rotateImage([[1, 2, 3], [4, 5, 6], [7, 8, 9]])) ===
+    JSON.stringify([[7, 4, 1], [8, 5, 2], [9, 6, 3]])
+);
+console.log(JSON.stringify(rotateImage([[1]])) === JSON.stringify([[1]]));
+console.log(JSON.stringify(rotateImage([[]])) === JSON.stringify([[]]));
+console.log(JSON.stringify(rotateImage([])) === JSON.stringify([]));