add Longest Repeating Character Replacement solution

Author: HoonDongKang

longest-repeating-character-replacement/HoonDongKang.ts

@@ -0,0 +1,27 @@
+/**
+ * [Problem]: [424] Longest Repeating Character Replacement
+ * (https://leetcode.com/problems/longest-repeating-character-replacement/description/)
+ */
+function characterReplacement(s: string, k: number): number {
+    //시간복잡도 O(n)
+    //공간복잡도 O(n)
+    let left = 0;
+    let right = 0;
+    let result = 0;
+    let map = new Map<string, number>();
+
+    while (right < s.length) {
+        map.set(s[right], (map.get(s[right]) || 0) + 1);
+
+        const maxFreq = Math.max(...Array.from(map.values()));
+        if (right - left + 1 - maxFreq > k) {
+            map.set(s[left], map.get(s[left])! - 1);
+            left++;
+        }
+
+        result = Math.max(result, right - left + 1);
+        right++;
+    }
+
+    return result;
+}