more robust and easier to understand.

Algorithms/yourname.github/Quick_Select_Algorithm.cpp

@@ -1,42 +1,46 @@
-#include<bits/stdc++.h>
+#include <bits/stdc++.h>
 using namespace std;
 
-int partition(int a[],int s,int e)
-{
-    int ind=s;
-    int pivot=a[e];
-
-    for(int i=s;i<e;i++)
-    {
-        if(a[i]<=pivot)
-            swap(a[i],a[ind++]);
+int partition(int a[], int s, int e) {
+    int pivot = a[e];
+    int ind = s;
+    for (int i = s; i < e; i++) {
+        if (a[i] <= pivot) {
+            swap(a[i], a[ind]);
+            ind++;
+        }
     }
-
-    swap(a[e],a[ind]);
-
+    swap(a[e], a[ind]);
     return ind;
 }
 
-int find_kth_smallest(int a[],int s,int e,int k)
-{
-    int pind=partition(a,s,e);
-
-    if(k>pind)
-        return find_kth_smallest(a,pind+1,e,k);
-    else if(k<pind)
-        return find_kth_smallest(a,s,pind-1,k);
-    else
-        return a[pind];
+int find_kth_smallest(int a[], int s, int e, int k) {
+    if (s <= e) {
+        int pind = partition(a, s, e);
+        if (pind == k) {
+            return a[pind];
+        } else if (pind > k) {
+            return find_kth_smallest(a, s, pind - 1, k);
+        } else {
+            return find_kth_smallest(a, pind + 1, e, k);
+        }
+    }
+    return INT_MAX; // Return a large value if k is out of bounds
 }
 
-int main()
-{
+int main() {
     int n;
-    cin>>n;
-    int a[n];
-    for(int i=0;i<n;i++)
-        cin>>a[i];
+    cin >> n;
+    vector<int> a(n);
+    for (int i = 0; i < n; i++) {
+        cin >> a[i];
+    }
     int k;
-    cin>>k;
-    cout<<find_kth_smallest(a,0,n-1,k-1);
-}
+    cin >> k;
+    if (k > 0 && k <= n) {
+        cout << find_kth_smallest(a.data(), 0, n - 1, k - 1) << endl;
+    } else {
+        cout << "Invalid value of k" << endl;
+    }
+    return 0;
+}