Merge pull request 'Implement all main exercises' (#1) from develop into main

Reviewed-on: #1

100 /100

.idea/misc.xml

@@ -8,7 +8,7 @@
       </list>
     </option>
   </component>
-  <component name="ProjectRootManager" version="2" project-jdk-name="25" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" project-jdk-name="25" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>

pom.xml

@@ -9,8 +9,8 @@
     <version>1.0-SNAPSHOT</version>
 
     <properties>
-        <maven.compiler.source>25</maven.compiler.source>
+        <maven.compiler.source>17</maven.compiler.source>
-        <maven.compiler.target>25</maven.compiler.target>
+        <maven.compiler.target>17</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
 

src/main/java/MainExercises.java

@@ -1,3 +1,7 @@
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Scanner;
+
 public class MainExercises
 {
     /*
@@ -19,10 +23,16 @@ public class MainExercises
     the output has to be a two-dimensional array of characters, so don't just print the triangle!
  */
     public char[][] generateTriangle(int n) {
-
+        char[][] tr = new char[n][];
-        // todo
+        for (int i = 0; i < n; i++) {
-        return null;
+            tr[i] = new char[i + 1];
-
+            for (int j = 0; j <= i; j++)
+                if (j == 0 || i == n - 1 || j == i)
+                    tr[i][j] = '*';
+                else
+                    tr[i][j] = ' ';
+        }
+        return tr;
     }
 
 
@@ -58,8 +68,30 @@ public class MainExercises
            - Number of columns: matrix[0].length (if rectangular)
    */
     public int[] spiralTraversal(int[][] matrix) {
-        // todo
+        if (matrix == null || matrix.length == 0)
-        return null;
+            return new int[0];
+        int rw = matrix.length, cl = matrix[0].length;
+        int[] res = new int[rw * cl];
+        int tp = 0, bt = rw - 1, l = 0, r = cl - 1, idx = 0;
+        while (tp <= bt && l <= r) {
+            for (int i = tp; i <= r; i++)
+                res[idx++] = matrix[tp][i];
+            tp++;
+            for (int i = tp; i <= bt; i++)
+                res[idx++] = matrix[i][r];
+            r--;
+            if (tp <= bt) {
+                for (int i = r; i >= l; i--)
+                    res[idx++] = matrix[bt][i];
+                bt--;
+            }
+            if (l <= r) {
+                for (int i = bt; i >= tp; i--)
+                    res[idx++] = matrix[i][l];
+                l++;
+            }
+        }
+        return res;
     }
 
     /*
@@ -91,13 +123,28 @@ public class MainExercises
     */
 
     public int[][] intPartitions(int n) {
-        // todo
+        List<List<Integer>> res = new ArrayList<>();
-        return null;
+        f(n, n, new ArrayList<>(), res);
+        int[][] a = new int[res.size()][];
+        for (int i = 0; i < res.size(); i++) {
+            List<Integer> r = res.get(i);
+            a[i] = new int[r.size()];
+            for (int j = 0; j < r.size(); j++) a[i][j] = r.get(j);
+        }
+        return a;
+    }
+    private void f(int t, int m, List<Integer> curr, List<List<Integer>> res) {
+        if (t == 0) {
+            res.add(new ArrayList<>(curr));
+            return;
+        }
+        for (int i = Math.min(t, m); i >= 1; i--) {
+            curr.add(i);
+            f(t - i, i, curr, res);
+            curr.remove(curr.size() - 1);
+        }
     }
 
-
+    public static void main() {
-    public static void main()
-    {
-
     }
 }