add: delete-overlapping-intervals

Author: supercodestart

README.md

@@ -1,6 +1,7 @@
 # JavaScript Assessments
 
 - [Convert string to group](convert-string-to-group)
+- [Delete Overlapping Intervals](delete-overlapping-intervals)
 - [Filling all the missed angle brackets](filling-all-the-missed-angle-brackets)
 - [Finding all the anagrams](finding-all-the-anagrams)
 - [Finding the maximum depth of a binary tree](finding-the-maximum-depth-of-a-binary-tree)

delete-overlapping-intervals/README.md

@@ -0,0 +1,24 @@
+# Delete Overlapping Intervals
+
+You are given a two-dimensional array `intervals`, as an argument.
+Each element of `intervals` represent an arbitrary interval, such as `[start, end]`.
+There are overlapping intervals in `intervals` and you need to combine the intervals so that they do not overlap.
+
+More specifically, the overlapping intervals are like below:
+
+```javascript
+intervals = [
+  [1, 3],
+  [2, 4],
+  [5, 7],
+];
+```
+
+In this example, `[1, 3]` which is `intervals[0]` and `[2, 4]` which is `intervals[1]` are overlapping intervals.
+By combining `intervals[0]` and `intervals[1]`, you can get `[1, 4]`.
+
+So output will be like below:
+
+```console
+[ [1, 4], [5, 7] ]
+```

delete-overlapping-intervals/solution.js

@@ -0,0 +1,40 @@
+const sortIntervals = ([aStart, aEnd], [bStart, bEnd]) =>
+  aStart > bStart || (aStart === bStart && aEnd > bEnd)
+    ? 1
+    : -1;
+
+const doIntersect = ([aStart, aEnd], [bStart, bEnd]) =>
+  aStart <= bEnd && aEnd >= bStart;
+
+const combineIntervals = (
+  [aStart, aEnd],
+  [bStart, bEnd],
+) => [Math.min(aStart, bStart), Math.max(aEnd, bEnd)];
+
+const solution = (intervals) =>
+  intervals
+    .sort(sortIntervals)
+    .reduce(
+      (merged, currentSeg) =>
+        merged.some((seg) => doIntersect(seg, currentSeg))
+          ? merged.map((seg) =>
+              doIntersect(seg, currentSeg)
+                ? combineIntervals(seg, currentSeg)
+                : seg,
+            )
+          : [...merged, currentSeg],
+      [],
+    );
+
+(() => {
+  console.log(
+    solution([
+      [2, 4],
+      [9, 13],
+      [3, 5],
+      [1, 3],
+      [5, 7],
+      [1, 2],
+    ]),
+  );
+})();