diff --git a/Find min in rotated sorted array/Solution.java b/Find min in rotated sorted array/Solution.java
new file mode 100644
index 0000000..14df913
--- /dev/null
+++ b/Find min in rotated sorted array/Solution.java	
@@ -0,0 +1,19 @@
+class Solution {
+    public int findMin(int[] nums) {
+     int start = 0;
+     int end =nums.length-1;
+     int mid=0;
+     while(start<=end){
+         mid=start+(end-start)/2;
+
+        if(nums[mid]>=nums[end]){
+            start=mid+1;
+        }
+        else {
+            end=mid;
+        }
+     }  
+
+     return nums[mid]; 
+    }
+}
\ No newline at end of file
diff --git a/best-time-to-buy-stock/Solution.java b/best-time-to-buy-stock/Solution.java
new file mode 100644
index 0000000..a60e40a
--- /dev/null
+++ b/best-time-to-buy-stock/Solution.java
@@ -0,0 +1,13 @@
+class Solution {
+    public int maxProfit(int[] prices) {
+        int max=0;
+        int minAmount=prices[0];
+
+        for(int i=1;i<prices.length;i++){
+           int profit=prices[i]-minAmount;
+            max=Math.max(max,profit);
+            minAmount=Math.min(minAmount,prices[i]);
+        }
+        return max;
+    }
+}
\ No newline at end of file
diff --git a/contains duplicate/Solution.java b/contains duplicate/Solution.java
new file mode 100644
index 0000000..f11850f
--- /dev/null
+++ b/contains duplicate/Solution.java	
@@ -0,0 +1,13 @@
+class Solution {
+    public boolean containsDuplicate(int[] nums) {
+        Set<Integer> hash = new HashSet<>();
+
+        for(int i =0;i<nums.length;i++){
+            if(!hash.add(nums[i])){
+                return true;
+            }
+        }
+
+        return false;
+    }
+}
\ No newline at end of file
diff --git a/max product subarray/Solution.java b/max product subarray/Solution.java
new file mode 100644
index 0000000..5bb417f
--- /dev/null
+++ b/max product subarray/Solution.java	
@@ -0,0 +1,17 @@
+class Solution {
+    public int maxProduct(int[] nums) {
+      int max=nums[0];
+      int min=nums[0];
+      int globalMax=nums[0];
+      for (int i =1;i<nums.length;i++){
+        
+        int tmp=max;
+        max=Math.max(nums[i],Math.max(max*nums[i],min*nums[i]));
+        min=Math.min(nums[i],Math.min(tmp*nums[i],min*nums[i]));
+
+        globalMax=Math.max(max,globalMax);
+      }
+
+      return globalMax;  
+    }
+}
\ No newline at end of file
diff --git a/max subarray/Solution.java b/max subarray/Solution.java
new file mode 100644
index 0000000..bae330f
--- /dev/null
+++ b/max subarray/Solution.java	
@@ -0,0 +1,22 @@
+class Solution {
+    public int maxSubArray(int[] nums) {
+      int max=nums[0];
+      int value=nums[0];
+      for(int i=1;i<nums.length;i++){
+        if(value<0){
+            if(nums[i]>=value){
+                value=nums[i];
+                max=Math.max(value,max);
+                continue;
+            }
+        }
+        else{
+            value+=nums[i];
+            max=Math.max(max,value);
+        }
+
+      }
+
+      return max;
+    }
+}
\ No newline at end of file
diff --git a/product of array/Solution.java b/product of array/Solution.java
new file mode 100644
index 0000000..f055007
--- /dev/null
+++ b/product of array/Solution.java	
@@ -0,0 +1,23 @@
+class Solution {
+    public int[] productExceptSelf(int[] nums) {
+        int[] arr=new int[nums.length];
+        int value=1;
+        int[] prod=new int[nums.length];
+        for(int i=0;i<nums.length;i++){
+            value*=nums[i];
+           arr[i]=value;
+        }
+
+        int j =1;
+        int k = arr.length-2;
+
+        for(int i=nums.length-1;i>0;i--){
+          
+          prod[i]=arr[k]*j;
+          j=j*nums[i];
+          k--;
+        }
+        prod[0]=j;
+        return prod;
+    }
+}
\ No newline at end of file
diff --git a/sum of integers/Solution.java b/sum of integers/Solution.java
new file mode 100644
index 0000000..07a30e7
--- /dev/null
+++ b/sum of integers/Solution.java	
@@ -0,0 +1,19 @@
+class Solution {
+    public int getSum(int a, int b) {
+        int carry =(a&b)<<1;
+       
+        int sum=a^b;
+        int total = sum ^ carry;
+
+        System.out.println(total);
+
+        while(carry!=0){
+            carry=(sum&carry)<<1;
+            sum=total;
+            total^=carry;
+            
+        }
+
+        return total;
+    }
+}
\ No newline at end of file
diff --git a/twosum/Solution.java b/twosum/Solution.java
new file mode 100644
index 0000000..2969d8f
--- /dev/null
+++ b/twosum/Solution.java
@@ -0,0 +1,19 @@
+class Solution {
+    public int[] twoSum(int[] nums, int target) {
+        int[] arr = new int[2];
+        Map<Integer,Integer> hash=new HashMap<>();
+
+        for(int i=0;i<nums.length;i++){
+            if(hash.containsKey(target-nums[i])){
+                arr[0]=hash.get(target-nums[i]);
+                arr[1]=i;
+                return arr;
+            }
+
+            hash.put(nums[i],i);
+        }
+
+        return arr;
+        
+    }
+}
\ No newline at end of file