diff --git a/Day-15/q3-Longest Increasing Subsequence/Shubh_Krishna_solution.cpp b/Day-15/q3-Longest Increasing Subsequence/Shubh_Krishna_solution.cpp
new file mode 100644
index 00000000..cd3a6298
--- /dev/null
+++ b/Day-15/q3-Longest Increasing Subsequence/Shubh_Krishna_solution.cpp	
@@ -0,0 +1,15 @@
+int lengthOfLIS(vector<int>& nums) {
+    int n=nums.size();
+    int lis[n];
+    lis[0]=1;
+    for(int i=1;i<n;i++)
+    {
+        lis[i]=1;
+        for(int j=0;j<i;j++){
+            if(nums[i]>nums[j] && lis[i]<lis[j]+1)
+                lis[i]=lis[j]+1;
+        }
+    }
+    return *max_element(lis,lis+n);
+}
+
diff --git a/Day-17/Q1:Determine if two strings are close/Subh_Krishna_solution.cpp b/Day-17/Q1:Determine if two strings are close/Subh_Krishna_solution.cpp
new file mode 100644
index 00000000..a07a1883
--- /dev/null
+++ b/Day-17/Q1:Determine if two strings are close/Subh_Krishna_solution.cpp	
@@ -0,0 +1,18 @@
+bool closeStrings(string word1, string word2) {
+    int cnt1[26]{};
+    int cnt2[26]{};
+    for (char& c : word1) {
+        ++cnt1[c - 'a'];
+    }
+    for (char& c : word2) {
+        ++cnt2[c - 'a'];
+    }
+    for (int i = 0; i < 26; ++i) {
+        if ((cnt1[i] == 0) != (cnt2[i] == 0)) {
+            return false;
+        }
+    }
+    sort(cnt1, cnt1 + 26);
+    sort(cnt2, cnt2 + 26);
+    return equal(cnt1, cnt1 + 26, cnt2);
+}
diff --git a/Day-18/q2:  Search in Rotated Sorted Array/Shubh_Krishna_solution.cpp b/Day-18/q2:  Search in Rotated Sorted Array/Shubh_Krishna_solution.cpp
new file mode 100644
index 00000000..8a9f8847
--- /dev/null
+++ b/Day-18/q2:  Search in Rotated Sorted Array/Shubh_Krishna_solution.cpp	
@@ -0,0 +1,25 @@
+int search(vector<int>& nums, int t) {
+        int ans=0,l=0,r=nums.size()-1,mid=0;
+        int n=nums.size()-1;
+    
+    
+    while(l<=r){
+        mid=(l+r)/2;
+        if(t==nums[mid]){return mid;}
+            if(nums[mid]>nums[n]){
+                if(t>nums[mid]||t<nums[0]){
+                    l=mid+1;
+                }else{
+                    r=mid-1;
+                }
+            }else{
+                if(t<nums[mid]||t>nums[n]){
+                    r=mid-1;
+                }else{
+                    l=mid+1;
+                }
+            }
+    }
+        
+    return -1;
+}
diff --git a/Day-22/q2: Sum of Left Leaves/Shubh_Krishna_solution.cpp b/Day-22/q2: Sum of Left Leaves/Shubh_Krishna_solution.cpp
new file mode 100644
index 00000000..77ebd089
--- /dev/null
+++ b/Day-22/q2: Sum of Left Leaves/Shubh_Krishna_solution.cpp	
@@ -0,0 +1,13 @@
+int sumOfLeftLeaves(struct TreeNode* root){
+    if (!root)
+        return 0;
+
+    int sum = 0;
+    if (root->left && !root->left->left && !root->left->right)
+        sum += root->left->val;
+    
+    sum+=sumOfLeftLeaves(root->left);
+    sum+=sumOfLeftLeaves(root->right);
+
+    return sum;
+}
diff --git a/Day-26/q2: Score of Parentheses/Shubh_Krishna_solution.cpp b/Day-26/q2: Score of Parentheses/Shubh_Krishna_solution.cpp
new file mode 100644
index 00000000..1c218d5a
--- /dev/null
+++ b/Day-26/q2: Score of Parentheses/Shubh_Krishna_solution.cpp	
@@ -0,0 +1,14 @@
+int scoreOfParentheses(string S) {
+        stack<int> stack;
+        int cur = 0;
+        for (char i : S)
+            if (i == '(') {
+                stack.push(cur);
+                cur = 0;
+            }
+            else {
+                cur += stack.top() + max(cur, 1);
+                stack.pop();
+            }
+        return cur;
+}