Issue #5479 resolved, Algorithm Frustum of Cone and tested it

src/main/java/com/thealgorithms/ciphers/Caesar.java

@@ -29,10 +29,10 @@ public String encode(String message, int shift) {
             char current = message.charAt(i); // Java law : char + int = char
 
             if (isCapitalLatinLetter(current)) {
-                current += shift;
+                current += (char) shift;
                 encoded.append((char) (current > 'Z' ? current - 26 : current)); // 26 = number of latin letters
             } else if (isSmallLatinLetter(current)) {
-                current += shift;
+                current += (char) shift;
                 encoded.append((char) (current > 'z' ? current - 26 : current)); // 26 = number of latin letters
             } else {
                 encoded.append(current);
@@ -56,10 +56,10 @@ public String decode(String encryptedMessage, int shift) {
         for (int i = 0; i < length; i++) {
             char current = encryptedMessage.charAt(i);
             if (isCapitalLatinLetter(current)) {
-                current -= shift;
+                current -= (char) shift;
                 decoded.append((char) (current < 'A' ? current + 26 : current)); // 26 = number of latin letters
             } else if (isSmallLatinLetter(current)) {
-                current -= shift;
+                current -= (char) shift;
                 decoded.append((char) (current < 'a' ? current + 26 : current)); // 26 = number of latin letters
             } else {
                 decoded.append(current);

src/main/java/com/thealgorithms/maths/AliquotSum.java

@@ -56,7 +56,7 @@ public static int getAliquotSum(int n) {
         // if n is a perfect square then its root was added twice in above loop, so subtracting root
         // from sum
         if (root == (int) root) {
-            sum -= root;
+            sum -= (int) root;
         }
         return sum;
     }

src/main/java/com/thealgorithms/maths/PerfectNumber.java

@@ -63,7 +63,7 @@ public static boolean isPerfectNumber2(int n) {
         // if n is a perfect square then its root was added twice in above loop, so subtracting root
         // from sum
         if (root == (int) root) {
-            sum -= root;
+            sum -= (int) root;
         }
 
         return sum == n;

src/main/java/com/thealgorithms/maths/Volume.java

@@ -90,4 +90,9 @@ public static double volumePrism(double baseArea, double height) {
     public static double volumePyramid(double baseArea, double height) {
         return (baseArea * height) / 3;
     }
+
+
+    public static double volumeFrustumOfCone(double r1, double r2, double height){
+        return (Math.PI * height / 3) * (r1 * r1 + r2 * r2 + r1 * r2);
+    }
 }

src/main/java/com/thealgorithms/maths/VolumeTest.java

@@ -0,0 +1,27 @@
+package com.thealgorithms.maths;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertTrue;
+
+public class VolumeTest {
+
+    @Test
+    public void volume(){
+
+//        test cube
+        assertTrue(Volume.volumeCube(7) == 343.0);
+        assertTrue(Volume.volumeCuboid(2, 5, 7) == 70.0);
+        assertTrue(Volume.volumeSphere(7) == 1436.7550402417319);
+        assertTrue(Volume.volumeCylinder(3, 7) == 197.92033717615698);
+        assertTrue(Volume.volumeHemisphere(7) == 718.3775201208659);
+        assertTrue(Volume.volumeCone(3, 7) == 65.97344572538566);
+        assertTrue(Volume.volumePrism(10, 2) == 20.0);
+        assertTrue(Volume.volumePyramid(10, 3) == 10.0);
+        assertTrue(Volume.volumeFrustumOfCone(3, 5, 7) == 359.188760060433);
+
+
+
+    }
+
+}