Add merge-intervals solution in TS

Author: Jeehay28

merge-intervals/Jeehay28.ts

@@ -0,0 +1,22 @@
+// TC: O(n * log n)
+// SC: O(n)
+function merge(intervals: number[][]): number[][] {
+  if (intervals.length === 0) return [];
+
+  intervals.sort((a, b) => a[0] - b[0]);
+
+  const merged = [intervals[0]];
+
+  for (let i = 1; i < intervals.length; i++) {
+    const last = merged[merged.length - 1];
+    const current = intervals[i];
+
+    if (current[0] <= last[1]) {
+      last[1] = Math.max(last[1], current[1]);
+    } else {
+      merged.push(intervals[i]);
+    }
+  }
+
+  return merged;
+}