Create display-table-of-food-orders-in-a-restaurant.cpp

Author: kamyu104

C++/display-table-of-food-orders-in-a-restaurant.cpp

@@ -0,0 +1,24 @@
+// Time:  O(n + tlogt + flogf)
+// Space: O(n)
+
+class Solution {
+public:
+    vector<vector<string>> displayTable(vector<vector<string>>& orders) {
+        map<int, unordered_map<string, int>> table_count;
+        set<string> foods;
+        for (const auto& order : orders) {
+            ++table_count[stoi(order[1])][order[2]];
+            foods.emplace(order[2]);
+        }
+        vector<vector<string>> result = {{"Table"}};
+        copy(foods.cbegin(), foods.cend(), back_inserter(result.back()));
+        for (const auto& kvp: table_count) {
+            result.push_back({to_string(kvp.first)});
+            transform(foods.cbegin(), foods.cend(), back_inserter(result.back()),
+                      [&kvp](const auto& food) {
+                          return to_string(kvp.second.count(food) ? kvp.second.at(food) : 0);
+                      });
+        }
+        return result;
+    }
+};