Add week 13 solutions: nonOverLappingIntervals, rotateImage

Author: yolophg

non-overlapping-intervals/yolophg.js

@@ -0,0 +1,23 @@
+// Time Complexity: O(n log n)
+// Space Complexity: O(1)
+
+var eraseOverlapIntervals = function (intervals) {
+  // sort the intervals based on their end times
+  intervals.sort((a, b) => a[1] - b[1]);
+
+  let end = intervals[0][1];
+  let count = 0;
+
+  // iterate through the sorted intervals
+  for (let i = 1; i < intervals.length; i++) {
+    if (intervals[i][0] < end) {
+      // overlapping interval found, increment the count
+      count++;
+    } else {
+      // no overlap, update the end to the current interval's end
+      end = intervals[i][1];
+    }
+  }
+
+  return count;
+};

rotate-image/yolophg.js

@@ -0,0 +1,31 @@
+// Time Complexity: O(n^2)
+// Space Complexity: O(1)
+
+var rotate = function (matrix) {
+  const n = matrix.length;
+
+  // perform the rotation layer by layer
+  for (let layer = 0; layer < Math.floor(n / 2); layer++) {
+    let first = layer;
+    let last = n - 1 - layer;
+
+    for (let i = first; i < last; i++) {
+      let offset = i - first;
+
+      // save the top element
+      let top = matrix[first][i];
+
+      // move left element to top
+      matrix[first][i] = matrix[last - offset][first];
+
+      // move bottom element to left
+      matrix[last - offset][first] = matrix[last][last - offset];
+
+      // move right element to bottom
+      matrix[last][last - offset] = matrix[i][last];
+
+      // assign saved top element to right
+      matrix[i][last] = top;
+    }
+  }
+};