Sync LeetCode submission - Decoded String at Index (cpp)

AC-Submissions/problems/decoded_string_at_index/solution.cpp

@@ -0,0 +1,30 @@
+class Solution {
+public:
+    std::string decodeAtIndex(string s, int k) {
+        long long length = 0;
+        int i = 0;
+
+        while (length < k) {
+            if (isdigit(s[i])) {
+                length *= s[i] - '0';
+            } else {
+                length++;
+            }
+            i++;
+        }
+
+        for (int j = i - 1; j >= 0; j--) {
+            if (isdigit(s[j])) {
+                length /= s[j] - '0';
+                k %= length;
+            } else {
+                if (k == 0 || k == length) {
+                    return std::string(1, s[j]); 
+                }
+                length--;
+            }
+        }
+
+        return "";
+    }
+};