add Non-overlapping Intervals solution

Author: HoonDongKang

non-overlapping-intervals/HoonDongKang.ts

@@ -0,0 +1,25 @@
+/**
+ * [Problem]: [435] Non-overlapping Intervals
+ * (https://leetcode.com/problems/non-overlapping-intervals/description/)
+ */
+
+//시간복잡도 O(n log n)
+//공간복잡도 O(1)
+function eraseOverlapIntervals(intervals: number[][]): number {
+    intervals.sort((a, b) => a[1] - b[1]);
+
+    let count = 0;
+    let prev = intervals[0][1];
+
+    for (let i = 1; i < intervals.length; i++) {
+        let [start, end] = intervals[i];
+
+        if (prev > start) {
+            count++;
+        } else {
+            prev = end;
+        }
+    }
+
+    return count;
+}