add tasks starting with a number

Task/100-doors/Java/100-doors-1.java

@@ -0,0 +1,13 @@
+public class HundredDoors {
+    public static void main(String[] args) {
+        boolean[] doors = new boolean[101];
+        for (int i = 1; i <= 100; i++) {
+            for (int j = i; j <= 100; j++) {
+                if(j % i == 0) doors[j] = !doors[j];
+            }
+        }
+        for (int i = 1; i <= 100; i++) {
+            System.out.printf("Door %d: %s%n", i, doors[i] ? "open" : "closed");
+        }
+    }
+}

Task/100-doors/Java/100-doors-2.java

@@ -0,0 +1,13 @@
+public class Doors
+{
+ public static void main(final String[] args)
+ {
+  boolean[] doors = new boolean[100];
+
+  for (int pass = 0; pass < 10; pass++)
+   doors[(pass + 1) * (pass + 1) - 1] = true;
+
+  for(int i = 0; i < 100; i++)
+   System.out.println("Door #" + (i + 1) + " is " + (doors[i] ? "open." : "closed."));
+ }
+}

Task/100-doors/Java/100-doors-3.java

@@ -0,0 +1,12 @@
+public class Doors
+{
+ public static void main(final String[] args)
+ {
+  StringBuilder sb = new StringBuilder();
+
+  for (int i = 1; i <= 10; i++)
+   sb.append("Door #").append(i*i).append(" is open\n");
+
+  System.out.println(sb.toString());
+ }
+}

Task/100-doors/Java/100-doors-4.java

@@ -0,0 +1,13 @@
+public class Doors{
+   public static void main(String[] args){
+      int i;		
+      for(i = 1; i < 101; i++){
+         double sqrt = Math.sqrt(i);
+         if(sqrt != (int)sqrt){
+            System.out.println("Door " + i + " is closed");
+         }else{
+            System.out.println("Door " + i + " is open");
+         }
+      }
+   } 	
+}