diff --git a/Longest Sub-Array with Sum K.cpp b/Longest Sub-Array with Sum K.cpp
new file mode 100644
index 0000000..fe919a1
--- /dev/null
+++ b/Longest Sub-Array with Sum K.cpp	
@@ -0,0 +1,49 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+
+// } Driver Code Ends
+class Solution{
+    public:
+    int lenOfLongSubarr(int A[],  int N, int K) 
+    { 
+        int sum=0;
+        unordered_map<int, int>mp;
+        int ans = 0;
+        for(int i=0; i<N; i++){
+            sum += A[i];
+            int diff = sum-K;
+            if(diff == 0)
+                ans = max(ans, i+1);
+            if(mp[diff])
+                ans = max(ans, i-mp[diff]+1);
+            if(!mp[sum])
+                mp[sum] = i+1;
+        }
+        return ans;
+    } 
+
+};
+
+//{ Driver Code Starts.
+
+int main() {
+	//code
+	
+	int t;cin>>t;
+	while(t--)
+	{
+	    int n, k;
+	    cin>> n >> k;
+	    int a[n];
+	    
+	    for(int i=0;i<n;i++)
+	        cin>>a[i];
+	   Solution ob;
+	   cout << ob.lenOfLongSubarr(a, n , k)<< endl;
+	    
+	}
+	
+	return 0;
+}
+// } Driver Code Ends