Problem on Sorting Algorithm

C++/Data-Structures/02-sorting-algorithms/Closest012.cpp

@@ -0,0 +1,53 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+void closest012(int arr[], int n)
+{
+    int lo = 0, hi = n - 1, mid = 0;
+    while (mid <= hi)
+    {
+        if (arr[mid] == 0)
+        {
+            swap(arr[lo], arr[mid]);
+            lo++;
+            mid++;
+        }
+        else if (arr[mid] == 1)
+        {
+            mid++;
+        }
+        else
+        {
+            swap(arr[mid], arr[hi]);
+            hi--;
+        }
+    }
+}
+int main()
+{
+
+    int t;
+    cin >> t;
+    while (t--)
+    {
+        int n;
+        cin >> n;
+        int arr[n];
+        for (int i = 0; i < n; i++)
+        {
+            cin >> arr[i];
+        }
+        closest012(arr, n);
+        for (int i = 0; i < n; i++)
+        {
+            cout << arr[i];
+        }
+        cout << endl;
+    }
+
+    return 0;
+}
+
+// Given an array of 0s, 1s, and 2s. Arrange the array elements such that all 0s come first, followed by all the 1s and then, all the 2s.
+// Input: N = 5, arr[] = {0, 2, 1, 2, 0}
+// Output: 0 0 1 2 2