Create apply-operations-to-make-string-empty.cpp

Author: kamyu104

C++/apply-operations-to-make-string-empty.cpp

@@ -0,0 +1,24 @@
+// Time:  O(n)
+// Space: O(1)
+
+// freq table
+class Solution {
+public:
+    string lastNonEmptyString(string s) {
+        vector<int> cnt(26);
+        for (const auto& x : s) {
+            ++cnt[x - 'a'];
+        }
+        string result;
+        const int mx = ranges::max(cnt);
+        for (int i = size(s) - 1; i >= 0; --i) {
+            if (cnt[s[i] - 'a'] != mx) {
+                continue;
+            }
+            --cnt[s[i] - 'a'];
+            result.push_back(s[i]);
+        }
+        reverse(begin(result), end(result));
+        return result;
+    }
+};