diff --git a/C++/quick-sort.cpp b/C++/quick-sort.cpp
new file mode 100644
index 0000000..1cb6b8c
--- /dev/null
+++ b/C++/quick-sort.cpp
@@ -0,0 +1,59 @@
+#include <iostream>
+#include <vector>
+
+void quick_sort(std::vector<int>& arr, int left, int right) {
+    if (left < right) {
+        int pivot = arr[left];  // Choose a pivot element (first element in this case)
+        int i = left;
+        int j = right;
+
+        while (i < j) {
+            while (i < j && arr[j] >= pivot) {
+                j--;
+            }
+            if (i < j) {
+                arr[i] = arr[j];
+                i++;
+            }
+
+            while (i < j && arr[i] <= pivot) {
+                i++;
+            }
+            if (i < j) {
+                arr[j] = arr[i];
+                j--;
+            }
+        }
+
+        arr[i] = pivot;
+
+        // Recursively sort the left and right sub-arrays
+        quick_sort(arr, left, i - 1);
+        quick_sort(arr, i + 1, right);
+    }
+}
+
+int main() {
+    std::vector<int> input_list;
+    int n;
+
+    std::cout << "Enter the number of elements: ";
+    std::cin >> n;
+
+    std::cout << "Enter " << n << " elements:\n";
+    for (int i = 0; i < n; i++) {
+        int element;
+        std::cin >> element;
+        input_list.push_back(element);
+    }
+
+    quick_sort(input_list, 0, n - 1);
+
+    std::cout << "Sorted list: ";
+    for (int i = 0; i < n; i++) {
+        std::cout << input_list[i] << " ";
+    }
+    std::cout << std::endl;
+
+    return 0;
+}
diff --git a/C++/sieve algorithm.cpp b/C++/sieve algorithm.cpp
new file mode 100644
index 0000000..a307289
--- /dev/null
+++ b/C++/sieve algorithm.cpp	
@@ -0,0 +1,32 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define ll long long
+const int N = 1e7 + 10;
+vector<bool> isprime(N,1);
+
+
+int main(){
+  
+    isprime[0]=false;isprime[1]=false;
+    for(int i=2; i<N; i++){
+        if(isprime[i]==true){
+            for(int j = 2*i; j<N; j+=i){
+                isprime[j]= false;
+            }
+        }
+    }
+
+
+    // Input the number to check whether prime or not
+
+    ll x;
+    cin>>x;
+
+    if(!isprime[x]){
+        cout<<x<<" is not prime number"<<endl;
+    }else{
+         cout<<x<<" is prime number"<<endl;
+    }
+
+  return 0;
+}
\ No newline at end of file