diff --git a/max_subarray.cpp b/max_subarray.cpp
new file mode 100644
index 0000000..02018fc
--- /dev/null
+++ b/max_subarray.cpp
@@ -0,0 +1,57 @@
+/* find the maximum of subarray */
+
+#include<bits/stdc++.h>
+using namespace std;
+
+unsigned long long maximum(unsigned long long arr[], unsigned long long n,unsigned long long k){
+	unsigned long long max=0;
+	for(unsigned long long i=0;i<k;i++){
+		if(max<arr[i])
+			max=arr[i];
+	}
+	return max;
+}
+
+int main(){
+	unsigned long long t,n,k,i,max,pos;
+	cin>>t;
+	while(t--){
+		cin>>n>>k;
+		unsigned long long arr[n];
+		max=0;
+		for(i=0;i<n;i++)
+			cin>>arr[i];
+		
+		for(unsigned long long i=0;i<k;i++){
+			if(max<arr[i]){
+				max=arr[i];
+				pos=i;
+			}
+		}
+		cout<<max<<" ";
+		
+		for(i=1;i<n-k+1;i++){
+			if(pos>=i){
+				if(max<arr[i+k-1]){
+					max=arr[i+k-1];
+					pos=i+k-1;
+				}
+				cout<<max<<" ";
+			}
+			else if(pos<i){
+				unsigned long long newmax=0;
+				for(unsigned long long j=i;j<i+k;j++){
+					if(newmax<arr[j]){
+						newmax=arr[j];
+						pos=j;
+					}
+				}
+				max=newmax;
+				cout<<max<<" ";
+			}
+		}
+		cout<<endl;
+
+	}
+
+}
\ No newline at end of file