diff --git a/src/main/java/com/dota/binarySearch/_1898/Solution.java b/src/main/java/com/dota/binarySearch/_1898/Solution.java
new file mode 100644
index 0000000..11a060c
--- /dev/null
+++ b/src/main/java/com/dota/binarySearch/_1898/Solution.java
@@ -0,0 +1,37 @@
+package com.dota.binarySearch._1898;
+
+class Solution {
+	public static void main(String[] args) {
+		new Solution().maximumRemovals("qlevcvgzfpryiqlwy", "qlecfqlw", new int[]{12,5});
+	}
+	public int maximumRemovals(String s, String p, int[] removable) {
+		int l = 0, r= removable.length + 1;
+		while(l+1<r) {
+			int mid = l+(r-l)/2;
+			if (check(s, p, removable, mid)) {
+				l = mid;
+			} else {
+				r = mid;
+			}
+		}
+		return l;
+	}
+
+	boolean check(String s, String p, int[] removable, int k) {
+		var cs = s.toCharArray();
+		for (int i = 0; i < k; i++) {
+			cs[removable[i]] = 0;
+		}
+		int l = 0;
+		for (char c : cs) {
+			if (c==p.charAt(l)) {
+				l++;
+			}
+			if (l==p.length()) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+}
\ No newline at end of file
diff --git a/src/main/java/com/dota/binarySearch/_2226/Solution.java b/src/main/java/com/dota/binarySearch/_2226/Solution.java
new file mode 100644
index 0000000..2a8a95e
--- /dev/null
+++ b/src/main/java/com/dota/binarySearch/_2226/Solution.java
@@ -0,0 +1,39 @@
+package com.dota.binarySearch._2226;
+
+class Solution {
+	public int maximumCandies(int[] candies, long k) {
+		long sum = 0;
+		int min = candies[0];
+		for (int candy : candies) {
+			min = Math.max(min, candy);
+			sum += candy;
+		}
+
+		if (sum < k) {
+			return 0;
+		}
+		if (sum == k) {
+			return 1;
+		}
+
+		int l = 0, r = min + 1;
+		while (l + 1 < r) {
+			int mid = l + (r - l) / 2;
+			if (check(candies, k, mid)) {
+				l = mid;
+			} else {
+				r = mid;
+			}
+		}
+		return l;
+	}
+
+	// k个小孩，每个x个
+	boolean check(int[] candies, long k, int x) {
+		long sum = 0;
+		for (int candy : candies) {
+			sum += candy / x;
+		}
+		return sum >= k;
+	}
+}
\ No newline at end of file
diff --git a/src/main/java/com/dota/binarySearch/_2576/Solution.java b/src/main/java/com/dota/binarySearch/_2576/Solution.java
new file mode 100644
index 0000000..a0b8219
--- /dev/null
+++ b/src/main/java/com/dota/binarySearch/_2576/Solution.java
@@ -0,0 +1,21 @@
+package com.dota.binarySearch._2576;
+
+import java.util.Arrays;
+
+class Solution {
+	public int maxNumOfMarkedIndices(int[] nums) {
+		Arrays.sort(nums);
+		int res = 0;
+		int mid = nums.length / 2;
+		int l = 0, r = mid + 1;
+		while (l < mid && r < nums.length) {
+			if (2*nums[l]<=nums[r]) {
+				res+=2;
+				l++;r++;
+			}else {
+				r++;
+			}
+		}
+		return res;
+	}
+}
\ No newline at end of file
diff --git a/src/main/java/com/dota/binarySearch/_275/Solution.java b/src/main/java/com/dota/binarySearch/_275/Solution.java
new file mode 100644
index 0000000..6c3b6a5
--- /dev/null
+++ b/src/main/java/com/dota/binarySearch/_275/Solution.java
@@ -0,0 +1,17 @@
+package com.dota.binarySearch._275;
+
+class Solution {
+    public int hIndex(int[] citations) {
+        int l = 0, r = citations.length - 1;
+        if (citations[r] == 0) return 0;
+        while (l < r) {
+            int mid = l + (r - l) / 2;
+            if (citations.length-mid > citations[mid]) {
+                l = mid + 1;
+            } else {
+                r  = mid;
+            }
+        }
+        return citations.length - r;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/dota/binarySearch/_2982/Solution.java b/src/main/java/com/dota/binarySearch/_2982/Solution.java
new file mode 100644
index 0000000..814542e
--- /dev/null
+++ b/src/main/java/com/dota/binarySearch/_2982/Solution.java
@@ -0,0 +1,43 @@
+package com.dota.binarySearch._2982;
+
+class Solution {
+	public static void main(String[] args) {
+		new Solution().maximumLength("abcaba");
+	}
+	public int maximumLength(String s) {
+		int l = -1, r = s.length();
+		while (l + 1 < r) {
+			int mid = l + (r - l) / 2;
+			if (check(s, mid)) {
+				l = mid;
+			} else {
+				r = mid;
+			}
+		}
+		return l==0?-1:l;
+	}
+
+	boolean check(String s, int k) {
+		var cs = s.toCharArray();
+		var sum = new int[26];
+		var dp = new int[26];
+		for (int i = 0; i < k; i++) {
+			dp[cs[i] - 'a']++;
+		}
+		if (dp[cs[0] - 'a'] == k) sum[cs[0]-'a'] = 1;
+		int l = 0, r = k;
+		while (r < s.length()) {
+			dp[cs[l] - 'a']--;
+			l++;
+			dp[cs[r] - 'a']++;
+			if (dp[cs[r] - 'a'] == k) {
+				sum[cs[r]-'a']++;
+				if (sum[cs[r]-'a'] >= 3) {
+					return true;
+				}
+			}
+			r++;
+		}
+		return false;
+	}
+}
\ No newline at end of file