Create 2349. Design a number container system

2349. Design a number container system

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+//2349. Design a number container system
+
+import java.util.NoSuchElementException;
+
+class NumberContainers {
+    Map<Integer, Integer> map;
+    Map<Integer, SortedSet<Integer>> valIdx;
+
+    public NumberContainers() {
+        map = new HashMap<>();
+        valIdx = new HashMap<>();
+    }
+
+    public void change(int index, int number) {
+        if(!valIdx.containsKey(number)) {
+            valIdx.put(number, new TreeSet<>());
+        }
+
+        if(map.containsKey(index)) {
+            int prevVal = map.get(index);
+            valIdx.get(prevVal).remove(index);
+        }
+
+        valIdx.get(number).add(index);
+        map.put(index, number);
+    }
+
+    public int find(int number) {
+        if(valIdx.containsKey(number)) {
+            try {
+                return valIdx.get(number).first();
+            }
+            catch(NoSuchElementException e) {
+                return -1;
+            }
+        }
+
+        return -1;
+    }
+}