cpp: add “1207. Unique Number of Occurrences”

Signed-off-by: Matej Focko <mfocko@redhat.com>

cpp/unique-number-of-occurrences.cpp

@@ -0,0 +1,21 @@
+#include <map>
+#include <set>
+#include <vector>
+
+class Solution {
+  public:
+    bool uniqueOccurrences(const std::vector<int> &arr) {
+        std::map<int, std::size_t> freqs;
+        for (const auto &x : arr) {
+            ++freqs[x];
+        }
+
+        // get unique values
+        std::set<std::size_t> unique_counts;
+        for (const auto &[key, count] : freqs) {
+            unique_counts.insert(count);
+        }
+
+        return freqs.size() == unique_counts.size();
+    }
+};