added problem with solution

Author: techie-khushdeep

.idea/runConfigurations.xml

@@ -0,0 +1,30 @@
+import java.util.Arrays;
+
+public class StringFormation {
+    public static void main(String[] args) {
+        StringFormation obj = new StringFormation();
+        System.out.println(Arrays.toString(obj.divideString("abcdefghij", 3, 'x')));
+    }
+    public String[] divideString(String s, int k, char fill) {
+
+        int length = s.length();
+
+        int arraySize =(int) Math.ceil((length*1.0)/k);
+        String[] str = new String[arraySize];
+
+        for(int i=0;i<s.length();i++){
+            int val = (int)Math.ceil(i/k);
+            if(str[val] == null){
+                str[val] = "";
+            }
+            str[val] += s.charAt(i);
+        }
+        for(int i=str[arraySize-1].length();i<k;i++){
+            str[arraySize-1] += fill;
+        }
+
+        return str;
+
+
+    }
+}

src/StringFormation.java

@@ -0,0 +1,12 @@
+package number_problem;
+//using bitwise
+public class EvenOrOdd {
+    public static void main(String[] args) {
+        int a= 17;
+        if((a &1)==1){//first a will be converted into binary and then and operation will happen
+            System.out.println("odd");
+        }else{
+            System.out.println("even");
+        }
+    }
+}

src/number_problem/EvenOrOdd.java

@@ -0,0 +1,4 @@
+package stack;
+
+public class ReverseAStackUsingRecursion {
+}

src/stack/ReverseAStackUsingRecursion.java

@@ -0,0 +1,19 @@
+package stack;
+
+import java.util.ArrayDeque;
+
+public class ReverseStringUsingStack {
+    public static void main(String[] args){
+        ArrayDeque<Character> input = new ArrayDeque<>();
+        String str = "ziuQskeeG";
+        for(byte index=0;index<str.length();index++){
+            input.push(str.charAt(index));
+        }
+        StringBuilder st = new StringBuilder();
+        while(input.peek()!=null){
+
+            st.append(input.pop());
+        }
+        System.out.println(st);
+    }
+}

src/stack/ReverseStringUsingStack.java

@@ -0,0 +1,16 @@
+package stack;
+
+public class ReverseStringWithoutStack {
+    public static void main(String[] args){
+        StringBuilder st = new StringBuilder("ziuQskeeG");
+        for(int i=0;i<st.length()/2;i++){
+            swap(st,i,st.length()-i-1);
+        }
+        System.out.println(st);
+    }
+    public static void swap(StringBuilder st,int index1,int index2){
+        char temp = st.charAt(index1);
+        st.setCharAt(index1,st.charAt(index2));
+        st.setCharAt(index2,temp);
+    }
+}

src/stack/ReverseStringWithoutStack.java

@@ -0,0 +1,26 @@
+package structure;
+
+import java.util.LinkedList;
+import java.util.PriorityQueue;
+import java.util.Queue;
+
+public class LearnStack {
+    public static void main(String[] args) {
+        PriorityQueue<Integer> pq = new PriorityQueue<>();
+        pq.add(20);
+        pq.add(10);
+        pq.add(50);
+        System.out.println(pq);
+
+        PriorityQueue<String> pq1 = new PriorityQueue<>();
+        pq1.add("Hello");
+        pq1.add("ABC");
+        pq1.add("Test");
+        System.out.println(pq1);
+
+        Queue<Integer> q1 = new LinkedList<>();
+        q1.add(20);
+        q1.add(10);
+        System.out.println(q1);
+    }
+}