Knapsack task

Author: ProgrammingLanguageLeader

src/algorithms/knapsack/Main.java

@@ -0,0 +1,58 @@
+package algorithms.knapsack;
+
+import java.util.Scanner;
+
+public class Main {
+    private final int MAX_CAPABILITY = 10000;
+    private final int MAX_SUBJECTS_NUMBER = 300;
+    private int[] subjectWeights = new int[MAX_SUBJECTS_NUMBER];
+    private int[][] knapsackMaxWeight = new int[MAX_CAPABILITY + 1][MAX_SUBJECTS_NUMBER + 1];
+
+    private int calcKnapsackMaxWeight(int knapsackCapability, int subjectsNumber) {
+        if (knapsackMaxWeight[knapsackCapability][subjectsNumber] != -1) {
+            return knapsackMaxWeight[knapsackCapability][subjectsNumber];
+        }
+
+        int firstWeight = calcKnapsackMaxWeight(knapsackCapability, subjectsNumber - 1);
+        knapsackMaxWeight[knapsackCapability][subjectsNumber - 1] = firstWeight;
+
+        int remainingKnapsackCapability = knapsackCapability - subjectWeights[subjectsNumber - 1];
+        if (remainingKnapsackCapability >= 0) {
+            int secondWeight = calcKnapsackMaxWeight(
+                    remainingKnapsackCapability,
+                    subjectsNumber - 1
+            ) + subjectWeights[subjectsNumber - 1];
+            knapsackMaxWeight[knapsackCapability][subjectsNumber - 1] = secondWeight;
+            return Integer.max(firstWeight, secondWeight);
+        }
+        return firstWeight;
+    }
+
+    private void init() {
+        for (int i = 0; i <= MAX_CAPABILITY; i++) {
+            for (int j = 0; j <= MAX_SUBJECTS_NUMBER; j++) {
+                if (i == 0 || j == 0) {
+                    knapsackMaxWeight[i][j] = 0;
+                } else {
+                    knapsackMaxWeight[i][j] = -1;
+                }
+            }
+        }
+    }
+
+    public void run() {
+        init();
+        Scanner scanner = new Scanner(System.in);
+        int knapsackCapability = scanner.nextInt();
+        int subjectsNumber = scanner.nextInt();
+        for (int i = 0; i < subjectsNumber; i++) {
+             subjectWeights[i] = scanner.nextInt();
+        }
+        int maxWeight = calcKnapsackMaxWeight(knapsackCapability, subjectsNumber);
+        System.out.println(maxWeight);
+    }
+
+    public static void main(String[] args) {
+        new Main().run();
+    }
+}