add data-structure of number container and priority manager

change example 3479

data-structure/number-containers.cpp

@@ -0,0 +1,35 @@
+#include <unordered_map>
+#include <queue>
+#include <vector>
+
+/*
+    The number container system can do the following:
+
+    1. insert or replace a number at the given index 
+    2. return the smallest index for the given number in the system
+
+*/
+
+class NumberContainers {
+private:
+    std::unordered_map<int, int> nums;
+    std::unordered_map<int, std::priority_queue<int, std::vector<int>, std::greater<int>>> heap;
+public:
+    NumberContainers() = default;
+
+    void change(int index, int number) {
+        nums[index] = number;
+        heap[number].push(index);
+    }
+
+    int find(int number) {
+        while (!heap[number].empty() && nums[heap[number].top()] != number) {
+            heap[number].pop();
+        }
+
+        if (heap[number].empty()) {
+            return -1;
+        }
+        return heap[number].top();
+    }
+};