cpp: add “2610. Convert an Array Into a 2D Array With Conditions”

Signed-off-by: Matej Focko <me@mfocko.xyz>

cpp/convert-an-array-into-a-2d-array-with-conditions.cpp

@@ -0,0 +1,35 @@
+#include <map>
+#include <vector>
+
+class Solution {
+public:
+    std::vector<std::vector<int>> findMatrix(const std::vector<int>& nums) {
+        // count the numbers
+        std::map<int, int> freqs;
+        for (auto x : nums) {
+            ++freqs[x];
+        }
+
+        std::vector<std::vector<int>> matrix;
+
+        bool elements_left = true;
+        while (elements_left) {
+            elements_left = false;
+
+            std::vector<int> row;
+            for (auto& [num, count] : freqs) {
+                if (count <= 0) {
+                    continue;
+                }
+
+                --count;
+                row.push_back(num);
+                elements_left = elements_left || count > 0;
+            }
+            matrix.push_back(row);
+        }
+
+        return matrix;
+    }
+};
+