Addition to Linked List Leetcode Problems

Added Design A Text Editor Problem. Leetcode-2296

Author: Enigma-52

CPP/LINKED LIST/SOME LEET CODE QUESTIONS/Design_a_Text_Editor.cpp

@@ -0,0 +1,82 @@
+#include <bits/stdc++.h>
+using namespace std;
+class TextEditor
+{
+private:
+    list<char> a;
+    // If delete, will delete position cur - 1, not position cur.
+    list<char>::iterator cur;
+
+public:
+    TextEditor()
+    {
+        a.clear();
+        // For convenience.
+        a.push_back('A');
+        cur = a.end();
+    }
+
+    void addText(string text)
+    {
+        a.insert(cur, text.begin(), text.end());
+    }
+
+    int deleteText(int k)
+    {
+        int cnt = 0;
+        // Move to the position that will be deleted.
+        cur--;
+        while (k--)
+        {
+            if (cur == a.begin())
+                break;
+            cnt++;
+            a.erase(cur--);
+        }
+        // Adjust the position of the cursor.
+        cur++;
+        return cnt;
+    }
+
+    // Left 10 chars.
+    string solve()
+    {
+        auto tt = cur;
+        tt--;
+        string ret;
+        int k = 10;
+        while (k--)
+        {
+            if (tt == a.begin())
+                break;
+            ret += (*(tt--));
+        }
+        reverse(ret.begin(), ret.end());
+        return ret;
+    }
+
+    string cursorLeft(int k)
+    {
+        while (k--)
+        {
+            auto nxt = cur;
+            nxt--;
+            // Never move the cursor to the first position.
+            if (nxt == a.begin())
+                break;
+            cur = nxt;
+        }
+        return solve();
+    }
+
+    string cursorRight(int k)
+    {
+        while (k--)
+        {
+            if (cur == a.end())
+                break;
+            cur++;
+        }
+        return solve();
+    }
+};