diff --git a/src/main/java/com/dota/greedy/_2712/Solution.java b/src/main/java/com/dota/greedy/_2712/Solution.java
new file mode 100644
index 0000000..4c04f35
--- /dev/null
+++ b/src/main/java/com/dota/greedy/_2712/Solution.java
@@ -0,0 +1,14 @@
+package com.dota.greedy._2712;
+
+class Solution {
+	public long minimumCost(String s) {
+		long res = 0;
+		int n = s.length();
+		for (int i =1; i < s.length(); i++) {
+			if (s.charAt(i-1) != s.charAt(i)) {
+				res += Math.min(i+1, n-i);
+			}
+		}
+		return res;
+	}
+}
\ No newline at end of file
diff --git a/src/main/java/com/dota/slidingWindow/_438/Solution.java b/src/main/java/com/dota/slidingWindow/_438/Solution.java
new file mode 100644
index 0000000..8b7f35c
--- /dev/null
+++ b/src/main/java/com/dota/slidingWindow/_438/Solution.java
@@ -0,0 +1,42 @@
+package com.dota.slidingWindow._438;
+
+import java.util.ArrayList;
+import java.util.List;
+
+class Solution {
+	public List<Integer> findAnagrams(String s, String p) {
+		if (s.length()<p.length()) {
+			return new ArrayList<>();
+		}
+		var list = new ArrayList<Integer>();
+		int k = p.length();
+		var dp = new int[26];
+		var book = new int[26];
+		for (int i = 0; i < k; i++) {
+			dp[p.charAt(i) - 'a']++;
+			book[s.charAt(i) - 'a']++;
+		}
+		if (check(dp,book)) {
+			list.add(0);
+		}
+
+		int l = 0;
+		for (int i = k; i <s.length() ; i++) {
+			book[s.charAt(l++) - 'a']--;
+			book[s.charAt(i) - 'a']++;
+			if (check(dp,book)) {
+				list.add(i-k+1);
+			}
+		}
+		return list;
+	}
+
+	boolean check(int[] a, int[]b) {
+		for (int i = 0; i < 26; i++) {
+			if (a[i] != b[i]) {
+				return false;
+			}
+		}
+		return true;
+	}
+}
\ No newline at end of file