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Author: starwiz-7

Day13.cpp

@@ -0,0 +1,49 @@
+/*
+    Author: Aryan Yadav
+    Remove K Digits
+
+    Complexity: O(n)
+    Algorithm: NA
+    Difficulty: Medium
+*/
+
+#include <bits/stdc++.h>
+using namespace std;
+class Solution
+{
+public:
+    string removeKdigits(string num, int k)
+    {
+        string result = "";
+
+        minnum(num, k, result);
+        result.erase(0, min(result.find_first_not_of('0'), result.size() - 1));
+        if (result.length() == 0)
+            result.push_back('0');
+        return result;
+    }
+
+    void minnum(string num, int k, string &result)
+    {
+        if (k == 0)
+        {
+            result.append(num);
+            return;
+        }
+        int len = num.length();
+        if (len <= k)
+        {
+            return;
+        }
+
+        int min = 0;
+        for (int i = 1; i <= k; i++)
+        {
+            if (num[i] < num[min])
+                min = i;
+        }
+        result.push_back(num[min]);
+        string new_str = num.substr(min + 1, len - min);
+        minnum(new_str, k - min, result);
+    }
+};