diff --git a/binary-search-for-the-answer/BinarySearchApp.java b/binary-search-for-the-answer/BinarySearchApp.java
new file mode 100644
index 0000000..9dcc686
--- /dev/null
+++ b/binary-search-for-the-answer/BinarySearchApp.java
@@ -0,0 +1,46 @@
+import java.util.Scanner;
+
+public class BinarySearchApp {
+
+    private int[] array;
+
+    private boolean Condition(int x, int k) {
+        int lines = 1;
+        int last_line = array[0];
+        for (int i = 0; i < array.length; i++) {
+            if (array[i] - last_line >= x) {
+                lines++;
+                last_line = array[i];
+            }
+        }
+        if (lines>k) return true;
+        else return false;
+    }
+
+    public int Solution(int k) {
+        int left = 0;
+        int right = array[array.length-1]-array[0]+1;
+        while (right - left > 1) {
+            int mid = (left + right) / 2;
+            if(Condition(mid, k)) {
+                left = mid;
+            } else {
+                right = mid;
+            }
+        }
+        return left;
+    }
+
+    public static void main(String[] args) {
+        BinarySearchApp binSearchForAnswer = new BinarySearchApp();
+        Scanner scanner = new Scanner(System.in);
+        int N = Integer.parseInt(scanner.nextLine());
+        int k = Integer.parseInt(scanner.nextLine()); 
+
+        binSearchForAnswer.array = new int[N];
+        for (int i = 0;i < N; i++) {
+            binSearchForAnswer.array[i] = Integer.parseInt(scanner.nextLine()); 
+        }
+        System.out.println(binSearchForAnswer.Solution(k));
+    }
+}
diff --git a/binary-search-tree/BinaryTree b/binary-search-tree/BinaryTree
new file mode 100644
index 0000000..ac7fc6d
--- /dev/null
+++ b/binary-search-tree/BinaryTree
@@ -0,0 +1,140 @@
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Scanner;
+
+public class BinaryTree {
+
+    Node root;
+
+    static class Node {
+        int value;
+        Node left;
+        Node right;
+
+        Node(int value) {
+            this.value = value;
+            right = null;
+            left = null;
+        }
+    }
+
+    public static void inTests(String fileIn, ArrayList<Integer> input) throws IOException {
+
+        Scanner sc = new Scanner(new File(fileIn));
+
+        while (sc.hasNextInt()) {
+            int str = sc.nextInt();
+            input.add(str);
+        }
+        sc.close();
+    }
+
+    
+      public static void outTests_min_after(String fileOut, ArrayList<String> output_contains, ArrayList<String> output_min_after) throws IOException {
+
+        FileWriter out = new FileWriter(fileOut);
+
+        for (int i = 0; i < output_contains.size(); i++) {
+            out.write(String.format("%s %s\n", output_contains.get(i), output_min_after.get(i)));
+        }
+        out.close();
+    }
+    public static void outTests_contains(String fileOut, ArrayList<String> output) throws IOException {
+
+        FileWriter out = new FileWriter(fileOut);
+
+        for (String sign : output) out.write(String.format("%s\n", sign));
+        out.close();
+    }
+
+  
+    public static void split(ArrayList<Integer> input, ArrayList<Integer> tree) {
+
+        int N = input.get(0);
+        for (int i = 0; i < N; i++) tree.add(i, input.get(i + 1));
+
+    }
+
+
+    private Node addRecursive(Node current, int value, ArrayList<String> output) {
+        if (current == null) {
+            output.add("-");
+            return new Node(value);
+        }
+
+        if (value < current.value) {
+            if (current.left != null) {
+                current.left = addRecursive(current.left, value, output);
+            } else {
+                current.left = new Node(value);
+                output.add("-");
+            }
+        } else if (value > current.value) {
+            if (current.right != null) {
+                current.right = addRecursive(current.right, value, output);
+            } else {
+                current.right = new Node(value);
+                output.add("-");
+            }
+        } else {
+            output.add("+");
+            return current;
+        }
+
+        return current;
+    }
+
+    public void addElement(int value, ArrayList<String> output) {
+        root = addRecursive(root, value, output);
+    }
+
+    /////////Поиск следующего элемента
+    public void findNext(int value, ArrayList<String> output) {
+        Node current = root;
+        Node next = null;
+        while (current != null) {
+            if (value >= current.value) {
+                current = current.right;
+            } else {
+                next = current;
+                current = current.left;
+            }
+        }
+        if (next != null) {
+            output.add(String.valueOf(next.value));
+        } else {
+            output.add("-");
+        }
+    }
+
+    private static void createBinaryTree(ArrayList<Integer> tree, ArrayList<String> output, ArrayList<String> output_min_after) {
+        BinaryTree bt = new BinaryTree();
+
+        for (Integer integer : tree) {
+            bt.addElement(integer, output);
+            bt.findNext(integer, output_min_after);
+        }
+    }
+
+    public static void main(String[] args) {
+
+        for (int i = 1; i <= 4; i++) {
+            ArrayList<Integer> input = new ArrayList<>();
+            ArrayList<Integer> tree = new ArrayList<>();
+            ArrayList<String> output_contains = new ArrayList<>();
+            ArrayList<String> output_min_after = new ArrayList<>();
+
+            try {
+                inTests(String.format("%d.in", i), input);
+                split(input, tree);
+                createBinaryTree(tree, output_contains, output_min_after);
+                outTests_contains(String.format("ans%d.contains.out", i), output_contains);
+                outTests_min_after(String.format("ans%d.min-after.out", i), output_contains, output_min_after);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}
diff --git a/binary-search/Main b/binary-search/Main
new file mode 100644
index 0000000..b767c85
--- /dev/null
+++ b/binary-search/Main
@@ -0,0 +1,75 @@
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Scanner;
+
+public class Main {
+
+    public static void InTests(String fileIn, ArrayList<Integer> input) throws IOException {
+
+        Scanner sc = new Scanner(new File(fileIn));
+
+        while (sc.hasNextInt()) {
+            int str = sc.nextInt();
+            input.add(str);
+        }
+        sc.close();
+    }
+
+
+    public static void outTests(String fileOut, ArrayList<Integer> output) throws IOException {
+
+        FileWriter out = new FileWriter(fileOut);
+
+        for (Integer integer : output) out.write(String.format("%d\n", integer));
+        out.close();
+    }
+    public static void split(ArrayList<Integer> input, ArrayList<Integer> arr, ArrayList<Integer> x_i) {
+
+        int N = input.get(0);
+        for (int i = 0; i<N; i++) arr.add(i, input.get(i + 1));
+
+        int K = input.get(N+1);
+        for (int i = 0; i<K; i++) x_i.add(i, input.get(i + N + 2));
+
+    }
+
+    public static void search(ArrayList<Integer> arr, ArrayList<Integer> x_i, ArrayList<Integer> output) {
+
+        for (int i = 0; i<x_i.size(); i++) {
+            int left = 0;
+            int right = arr.size()-1;
+            int mid = (left + right) / 2;
+            while ((!arr.get(mid).equals(x_i.get(i))) && (left <= right)) {
+
+                if (arr.get(mid) > x_i.get(i)) {
+                    right = mid - 1;
+                } else left = mid + 1;
+                mid = (left + right) / 2;
+            }
+            if (left <= right) {
+                output.add(i, mid);
+            } else output.add(i, -1);
+        }
+    }
+
+    public static void main(String[] args) {
+
+        for (int i = 1; i <= 5; i++) {
+            ArrayList<Integer> input = new ArrayList<>();
+            ArrayList<Integer> arr = new ArrayList<>();
+            ArrayList<Integer> x_i = new ArrayList<>();
+            ArrayList<Integer> output = new ArrayList<>();
+
+            try {
+                InTests(String.format("%d.in", i), input);
+                split(input, arr, x_i);
+                search(arr, x_i, output);
+                OutTests(String.format("ans%d.out", i), output);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}
diff --git a/coins-system/coinSystem b/coins-system/coinSystem
new file mode 100644
index 0000000..783ab67
--- /dev/null
+++ b/coins-system/coinSystem
@@ -0,0 +1,113 @@
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Scanner;
+
+public class Mavenproject4 {
+
+    public static boolean InTests (String fileIn, ArrayList<Integer> input) throws IOException {
+
+        File file = new File(fileIn);
+        if (file.exists()) {
+            Scanner sc = new Scanner(file);
+            while (sc.hasNextInt()) {
+                int str = sc.nextInt();
+                input.add(str);
+            }
+            sc.close();
+            return true;
+        } else return false;
+    }
+
+    
+      public static void outTests(String fileOut, ArrayList<Integer> output) throws IOException {
+
+        FileWriter out = new FileWriter(fileOut);
+
+        for (Integer integer : output) out.write(String.format("%d\n", integer));
+        out.close();
+    }
+ 
+      
+      
+    public static void split(ArrayList<Integer> input, ArrayList<Integer> nominal, int k, ArrayList<Integer> nominalSort) {
+
+        for (int i = 0; i < k; i++) {
+            nominal.add(i, input.get(i + 1));
+            nominalSort.add(i, input.get(i + 1));
+        }
+
+    }
+
+
+    
+    public static void findCoins(ArrayList<Integer> nominalSort, int sum, ArrayList<Integer> coinsMin, ArrayList<Integer> coinsUsed) {
+        int coinCount;
+
+        Collections.sort(nominalSort);
+        for (int i = 0; i <= sum + 1; i++) {
+            coinCount = i;
+            int newCoin = nominalSort.get(0);
+
+            for (int j : nominalSort) {
+                if (j > i) {
+                    continue;
+                }
+                if (coinsMin.get(i - j) + 1 < coinCount) {
+                    coinCount = coinsMin.get(i - j) + 1;
+                    newCoin = j;
+                }
+            }
+            coinsMin.add(i, coinCount);
+            coinsUsed.add(i, newCoin);
+        }
+    }
+
+
+    public static void countCoins(ArrayList<Integer> nominal, int sum, ArrayList<Integer> coinsMin, ArrayList<Integer> coinsUsed, ArrayList<Integer> output) {
+
+        int coin = sum;
+        //Минимальное количество монет
+        output.set(0, coinsMin.get(sum));
+        //Подсчет использованных монет
+        while (coin > 0) {
+            if (nominal.contains(coinsUsed.get(coin))) {
+                int position = nominal.indexOf(coinsUsed.get(coin)) + 1;
+                output.set(position, output.get(position) + 1);
+                coin = coin - coinsUsed.get(coin);
+            }
+        }
+        if (coin < 0) {
+            output.clear();
+            output.add(-1);
+        }
+    }
+
+
+    
+    public static void main(String[] args) {
+
+        for (int i = 1; i <= 26; i++) {
+            ArrayList<Integer> input = new ArrayList<>();
+            ArrayList<Integer> nominal = new ArrayList<>();
+            ArrayList<Integer> coinsMin = new ArrayList<>();
+            ArrayList<Integer> coinsUsed = new ArrayList<>();
+            ArrayList<Integer> nominalSort = new ArrayList<>();
+            try {
+                if (InTests(String.format("%d.in", i), input)) {
+                    int k = input.get(0);
+                    int N = input.get(input.size() - 1);
+                    ArrayList<Integer> output = new ArrayList<>(Collections.nCopies(k + 1, 0));
+                    split(input, nominal, k, nominalSort);
+                    findCoins(nominalSort, N, coinsMin, coinsUsed);
+                    countCoins(nominal, N, coinsMin, coinsUsed, output);
+                    outTests(String.format("out/ans%d.full-answer.out", i), output);
+                }
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}