diff --git a/Insertion_Sort.cpp b/Insertion_Sort.cpp
index bf8c6ed..769a5f7 100644
--- a/Insertion_Sort.cpp
+++ b/Insertion_Sort.cpp
@@ -38,7 +38,7 @@ void insertionSort(int arr[], int n) {
 int main() {
 
     int n;
-    cout<<"Enter number of elements : ";
+    cout<<"Enter the number of elements : ";
     cin>>n;
 
     int arr[n];
diff --git a/Kadanes_Algo b/Kadanes_Algo
new file mode 100644
index 0000000..d788079
--- /dev/null
+++ b/Kadanes_Algo
@@ -0,0 +1,20 @@
+#include <iostream>
+using namespace std;
+int main()
+{
+    int n;
+    cin >> n;
+    int ms = 0, cs = 0;
+    int arr[n];
+    for (int i = 0; i < n; i++)
+    {
+        cin >> arr[i];
+        cs += arr[i];
+        if (cs < 0)
+            cs = 0;
+        else if (cs >= ms)
+            ms = cs;
+    }
+    cout << ms << endl;
+    return 0;
+}
diff --git a/LongestCommonSubsequence.cpp b/LongestCommonSubsequence.cpp
new file mode 100644
index 0000000..6b6a574
--- /dev/null
+++ b/LongestCommonSubsequence.cpp
@@ -0,0 +1,38 @@
+#include <iostream>
+#include <cstring>
+#include <bits/stdc++.h>
+using namespace std;
+
+//finding max value
+int max(int a, int b)
+{
+    return (a > b) ? a : b;
+}
+
+//finding LCS
+int LongestCommonSubsequence(char *str1, char *str2, int x, int y)
+{
+    if (x == 0 || y == 0)
+    {
+        return 0;
+    }
+    if (str1[x - 1] == str2[y - 1])
+    {
+        return (1 + LongestCommonSubsequence(str1, str2, x - 1, y - 1));
+    }
+    else
+    {
+        return max(LongestCommonSubsequence(str1, str2, x, y - 1), LongestCommonSubsequence(str1, str2, x - 1, y));
+    }
+}
+
+//main function
+int main()
+{
+    char str1[] = "cantonment";
+    char str2[] = "longatone";
+    int x = strlen(str1);
+    int y = strlen(str2);
+    cout << "\nLength of Longest Common Subsequence From Both The Strings Is " << LongestCommonSubsequence(str1, str2, x, y) << endl;
+    return 0;
+}
\ No newline at end of file
diff --git a/Stack using linked list.c b/Stack using linked list.c
new file mode 100644
index 0000000..c3f9864
--- /dev/null
+++ b/Stack using linked list.c	
@@ -0,0 +1,106 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+struct Node
+{
+    int data;
+    struct Node *next;
+};
+
+struct Node *head = NULL;
+
+void push(int value)
+{
+    struct Node *n = (struct Node *)malloc(sizeof(struct Node *));
+    if (head == NULL)
+    {
+        head = n;
+        n->data = value;
+        n->next = NULL;
+        return;
+    }
+
+    n->next = head;
+    n->data = value;
+    head = n;
+}
+
+void pop()
+{
+    struct Node *temp = head;
+    if (head == NULL)
+    {
+        printf("\nStack is empty.\n");
+        return;
+    }
+
+    head = head->next;
+    temp->next = NULL;
+}
+
+void peek()
+{
+    if (head == NULL)
+    {
+        printf("\nStack is empty.\n");
+        return;
+    }
+
+    printf("The top element is: %d\n", head->data);
+}
+
+void display()
+{
+    struct Node *temp = head;
+    if (head == NULL)
+    {
+        printf("\nStack is empty.\n");
+        return;
+    }
+    printf("\nElements of stack are:\n");
+    while (temp != NULL)
+    {
+        printf("%d\n", temp->data);
+        temp = temp->next;
+    }
+}
+
+int main()
+{
+    while (1)
+    {
+        printf("\n=======Menu=======\n");
+        printf("1. Push\n");
+        printf("2. Pop\n");
+        printf("3. Peek\n");
+        printf("4. Display\n");
+        printf("5. Exit\n\n");
+        int c, n;
+        scanf("%d", &c);
+        switch (c)
+        {
+        case 1:
+            printf("Enter the element to be inserted: ");
+            scanf("%d", &n);
+            push(n);
+            break;
+        case 2:
+            pop();
+            break;
+        case 3:
+            peek();
+            break;
+        case 4:
+            display();
+            break;
+        case 5:
+            exit(0);
+            break;
+
+        default:
+            printf("Please select a valid option.");
+        }
+    }
+
+    return 0;
+}
\ No newline at end of file
diff --git a/ZigZagPattern.cpp b/ZigZagPattern.cpp
new file mode 100644
index 0000000..e345f7f
--- /dev/null
+++ b/ZigZagPattern.cpp
@@ -0,0 +1,67 @@
+#include <iostream>
+using namespace std;
+
+int main()
+{
+
+    int n;
+    cin >> n;
+
+    for (int i = 1; i <= 3; i++)
+    {
+        if (i == 1)
+        {
+            int c = 0;
+            for (int j = 1; j <= n; j++)
+            {
+                if (j == 1 || j == 2)
+                {
+                    cout << "  ";
+                }
+                else
+                {
+                    if (c % 4 == 0)
+                    {
+                        cout << "* ";
+                    }
+                    else
+                    {
+                        cout << "  ";
+                    }
+                    c++;
+                }
+            }
+        }
+        else if (i == 2)
+        {
+            for (int j = 1; j <= n; j++)
+            {
+                if (j % 2 == 0)
+                {
+                    cout << "* ";
+                }
+                else
+                {
+                    cout << "  ";
+                }
+            }
+        }
+        else
+        {
+            for (int j = 1; j <= n; j++)
+            {
+                if (j % 4 == 1)
+                {
+                    cout << "* ";
+                }
+                else
+                {
+                    cout << "  ";
+                }
+            }
+        }
+        cout << endl;
+    }
+
+    return 0;
+}
\ No newline at end of file
diff --git a/longest_common_subsequence_using_dp.cpp b/longest_common_subsequence_using_dp.cpp
new file mode 100644
index 0000000..cf862e8
--- /dev/null
+++ b/longest_common_subsequence_using_dp.cpp
@@ -0,0 +1,73 @@
+//here i am providing two solutions to the following problems using dynamic programming
+//one is Top-Down DP and another is Bottom-Up DP
+// this paticular questions corresponds to the folloing question on leetcode
+//leetcode-1143 https://leetcode.com/problems/longest-common-subsequence/
+//here i have explained the question in a gradual optimal manner
+//------------------------------------------------------------------------------------------------------------------
+//brute force approach
+class Solution {
+    public int longestCommonSubsequence(String text1, String text2) {
+        return longestCommonSubsequence(text1, text2, 0, 0);
+    }
+    
+    private int longestCommonSubsequence(String text1, String text2, int i, int j) {
+        if (i == text1.length() || j == text2.length())
+            return 0;
+        if (text1.charAt(i) == text2.charAt(j))
+            return 1 + longestCommonSubsequence(text1, text2, i + 1, j + 1);
+        else
+            return Math.max(
+                longestCommonSubsequence(text1, text2, i + 1, j),
+                longestCommonSubsequence(text1, text2, i, j + 1)
+            );
+    }
+}
+//------------------------------------------------------------------------------------------------------------------
+/* Top-down DP
+We might use memoization to overcome overlapping subproblems.
+Since there are two changing values, i.e. i and j in the recursive 
+function longestCommonSubsequence, we might apply a two-dimensional array.*/
+class Solution {
+    private Integer[][] dp;
+    public int longestCommonSubsequence(String text1, String text2) {
+        dp = new Integer[text1.length()][text2.length()];
+        return longestCommonSubsequence(text1, text2, 0, 0);
+    }
+    
+    private int longestCommonSubsequence(String text1, String text2, int i, int j) {
+        if (i == text1.length() || j == text2.length())
+            return 0;
+        
+        if (dp[i][j] != null)
+            return dp[i][j];
+            
+        if (text1.charAt(i) == text2.charAt(j))
+            return dp[i][j] = 1 + longestCommonSubsequence(text1, text2, i + 1, j + 1);
+        else
+            return dp[i][j] = Math.max(
+                longestCommonSubsequence(text1, text2, i + 1, j),
+                longestCommonSubsequence(text1, text2, i, j + 1)
+            );
+    }
+}
+//------------------------------------------------------------------------------------------------------------------
+/*Bottom-up DP
+For every i in text1, j in text2, we will choose one of the following two options:
+
+if two characters match, length of the common subsequence would be 1 plus the 
+length of the common subsequence till the i-1 andj-1 indexes
+if two characters doesn't match, we will take the longer by either skipping i or j indexes*/
+class Solution {
+    public int longestCommonSubsequence(String text1, String text2) {
+        int[][] dp = new int[text1.length() + 1][text2.length() + 1];
+        for (int i = 1; i <= text1.length(); i++) {
+            for (int j = 1; j <= text2.length(); j++) {
+                if (text1.charAt(i - 1) == text2.charAt(j - 1))
+                    dp[i][j] = 1 + dp[i - 1][j - 1];
+                else
+                    dp[i][j] = Math.max(dp[i - 1][j], dp[i][j - 1]);
+            }
+        }
+        return dp[text1.length()][text2.length()];
+    }
+}
\ No newline at end of file
diff --git a/rat_in_maze.cpp b/rat_in_maze.cpp
new file mode 100644
index 0000000..808a791
--- /dev/null
+++ b/rat_in_maze.cpp
@@ -0,0 +1,75 @@
+#include<iostream>
+using namespace std;
+
+bool isSafe(int** arr, int x, int y, int n){
+
+    if( x<n && y<n && arr[x][y]==1) {
+        return true;
+    }
+
+    return false;
+}
+
+bool ratinmaze(int** arr, int x, int y, int n, int** solArr){
+
+    if( ( x == (n-1) && y == (n-1) )){
+        solArr[x][y]=1;
+        return true;
+    }
+
+    if( isSafe(arr,x,y,n)){
+
+        solArr[x][y]=1;
+
+        if( ratinmaze(arr,x+1,y,n,solArr) ){
+            return true;
+        }
+        if( ratinmaze(arr,x,y+1,n,solArr) ){
+            return true;
+        }
+
+        solArr[x][y]=0;
+        return false;
+    }
+
+    return false;
+}
+
+
+int main(){
+
+    int n;
+    cin>>n;
+
+    int** arr = new int*[n];
+    for(int i=0; i<n; i++){
+        arr[i] = new int[n];
+    }
+
+    for(int i=0; i<n; i++){
+        for (int j=0; j<n; j++){
+            cin>>arr[i][j];
+        }
+    }
+
+    int** solArr = new int*[n];
+    for(int i=0; i<n; i++){
+        solArr[i] = new int[n];
+        for (int j=0; j<n; j++){
+            solArr[i][j]=0;
+        }
+    }
+
+    cout<<endl;
+
+    if(ratinmaze(arr,0,0,n,solArr)){
+        for(int i=0; i<n; i++){
+            for (int j=0; j<n; j++){
+                cout<<solArr[i][j]<<" ";
+            }
+            cout<<endl;
+        }
+    }
+
+    return 0;
+}
\ No newline at end of file
diff --git a/stack_linkedlist.cpp b/stack_linkedlist.cpp
new file mode 100644
index 0000000..5022a8b
--- /dev/null
+++ b/stack_linkedlist.cpp
@@ -0,0 +1,82 @@
+/* C++ program to implement basic stack
+operations */
+#include <bits/stdc++.h>
+
+using namespace std;
+
+#define MAX 1000
+
+class Stack {
+	int top;
+
+public:
+	int a[MAX]; // Maximum size of Stack
+
+	Stack() { top = -1; }
+	bool push(int x);
+	int pop();
+	int peek();
+	bool isEmpty();
+};
+
+bool Stack::push(int x)
+{
+	if (top >= (MAX - 1)) {
+		cout << "Stack Overflow";
+		return false;
+	}
+	else {
+		a[++top] = x;
+		cout << x << " pushed into stack\n";
+		return true;
+	}
+}
+
+int Stack::pop()
+{
+	if (top < 0) {
+		cout << "Stack Underflow";
+		return 0;
+	}
+	else {
+		int x = a[top--];
+		return x;
+	}
+}
+int Stack::peek()
+{
+	if (top < 0) {
+		cout << "Stack is Empty";
+		return 0;
+	}
+	else {
+		int x = a[top];
+		return x;
+	}
+}
+
+bool Stack::isEmpty()
+{
+	return (top < 0);
+}
+
+// Driver program to test above functions
+int main()
+{
+	class Stack s;
+	s.push(10);
+	s.push(20);
+	s.push(30);
+	cout << s.pop() << " Popped from stack\n";
+	//print all elements in stack :
+	cout<<"Elements present in stack : ";
+	while(!s.isEmpty())
+	{
+		// print top element in stack
+		cout<<s.peek()<<" ";
+		// remove top element in stack
+		s.pop();
+	}
+
+	return 0;
+}