added left-rotation.cpp file (#84)

* added left-rotation.cpp file

* Update README.md

Added a link for left-rotation.cpp

arrays/README.md

@@ -1,18 +1,19 @@
-# Algorithms related to arrays
-
-### C or C++
-
-1. [Counting Inversions](c-or-cpp/count-inversions.cpp)
-2. [Dutch Flag Algo](c-or-cpp/dutch-flag-algo.cpp)
-
-### Python
-
-1. [Counting Inversions](python/count-inversions.py)
-
-### JavaScript
-
-1. [Counting Inversions](js/count-inversions.js)
-
-### Java
-
-1. [Counting Inversions](java/count-inversions.java)
+# Algorithms related to arrays
+
+### C or C++
+
+1. [Counting Inversions](c-or-cpp/count-inversions.cpp)
+2. [Dutch Flag Algo](c-or-cpp/dutch-flag-algo.cpp)
+3. [Left Rotation of Array](c-or-cpp/left-rotation.cpp)
+
+### Python
+
+1. [Counting Inversions](python/count-inversions.py)
+
+### JavaScript
+
+1. [Counting Inversions](js/count-inversions.js)
+
+### Java
+
+1. [Counting Inversions](java/count-inversions.java)

arrays/c-or-cpp/left-rotation.cpp

@@ -0,0 +1,33 @@
+#include <bits/stdc++.h>
+
+#define int long long int
+#define pb push_back
+using namespace std;
+
+signed main()
+{
+    ios_base::sync_with_stdio(0);
+    cin.tie(0);
+    int n,left_rotation_val;
+    cin>>n>>left_rotation_val;
+    int arr[n];
+    for (int i = 0; i < n; i++)
+    {
+        cin>>arr[i];
+    }
+
+    left_rotation_val = left_rotation_val % n;
+    //Doing this we can get the place from where the rotation starts.
+    // 5 4
+    // 1 2 3 4 5
+    // 1 2 3 4 5 -> 2 3 4 5 1(1 rotation) -> 3 4 5 1 2(2 rotation) -> 4 5 1 2 3(3 rotation) -> 5 1 2 3 4(4 rotation)
+
+    for(int i = left_rotation_val; i<n; i++){
+        cout<<arr[i]<<" ";
+    }
+
+    for(int i = 0;i<left_rotation_val;i++){
+        cout<<arr[i]<<" ";
+    }
+    
+}