diff --git a/src/main/java/com/dota/binarySearch/_2861/Solution.java b/src/main/java/com/dota/binarySearch/_2861/Solution.java
new file mode 100644
index 0000000..343f467
--- /dev/null
+++ b/src/main/java/com/dota/binarySearch/_2861/Solution.java
@@ -0,0 +1,50 @@
+package com.dota.binarySearch._2861;
+
+import java.util.List;
+
+class Solution {
+	public static void main(String[] args) {
+		new Solution().maxNumberOfAlloys(1,2,24308609, List.of(List.of(40), List.of(88)),List.of(82685338),List.of(2));
+	}
+	public int maxNumberOfAlloys(int n, int k, int budget, List<List<Integer>> composition, List<Integer> stock, List<Integer> cost) {
+		int max = 0;
+		for (Integer i : stock) {
+			max = Math.max(max, i);
+		}
+		int i = 0, j = budget + 1 + max;
+		while (i + 1 < j) {
+			int mid = i + (j - i) / 2;
+			if (check(mid, budget, composition, stock, cost)) {
+				i = mid;
+			} else {
+				j = mid;
+			}
+		}
+		return i;
+	}
+
+	// 主要看钱够不够造k份合金
+	boolean check(int k, long budget, List<List<Integer>> composition, List<Integer> stock, List<Integer> cost) {
+		long t = budget;
+		for (List<Integer> integers : composition) {
+			budget = t;
+			for (int j = 0; j < integers.size(); j++) {
+				if ((long)stock.get(j) >= (long) k * integers.get(j)) {
+					continue;
+				}
+
+				long a = (long) k * integers.get(j)  - stock.get(j);
+				long b = a * cost.get(j);
+				if (budget < b) {
+					budget = - 1;
+					break;
+				}
+				budget -= b;
+			}
+			if (budget >= 0) {
+				return true;
+			}
+		}
+		return false;
+	}
+}
\ No newline at end of file
diff --git a/src/main/java/com/dota/stack/_3170/Solution.java b/src/main/java/com/dota/stack/_3170/Solution.java
new file mode 100644
index 0000000..76b6c62
--- /dev/null
+++ b/src/main/java/com/dota/stack/_3170/Solution.java
@@ -0,0 +1,31 @@
+package com.dota.stack._3170;
+
+import java.util.Comparator;
+import java.util.HashSet;
+import java.util.PriorityQueue;
+
+class Solution {
+	public String clearStars(String s) {
+		var stack = new PriorityQueue<Integer>((a,b)->{
+			if (s.charAt(a)==s.charAt(b)) {
+				return b - a;
+			}
+			return s.charAt(a) - s.charAt(b);
+		});
+		for (int i = 0; i < s.length(); i++) {
+			if (s.charAt(i) == '*') {
+				stack.poll();
+			} else {
+				stack.add(i);
+			}
+		}
+		var set = new HashSet<>(stack);
+		var sb = new StringBuilder();
+		for (int i = 0; i < s.length(); i++) {
+			if (set.contains(i)) {
+				sb.append(s.charAt(i));
+			}
+		}
+		return sb.toString();
+	}
+}
\ No newline at end of file