- Add: Java Time Based Key-Value Store

Author: BNSC1

LeetCode/981. Time Based Key-Value Store.java

@@ -0,0 +1,52 @@
+class TimeMap {
+    Map<String, List<Data>> map = new HashMap<>() {
+        @Override
+        public List<Data> get(Object key) {
+            if (!containsKey(key)) return new ArrayList<Data>();
+            else return super.get(key);
+        }
+    };
+
+    public TimeMap() {} //SC: O(n), where n is the number of timestamp data
+
+    public void set(String key, String value, int ts) {
+        if (!map.containsKey(key)) {
+            map.put(key, new ArrayList<>());
+        }
+        map.get(key).add(new Data(value, ts));
+    } //TC: O(1)
+
+    public String get(String key, int ts) {
+        List<Data> values = map.get(key);
+        String res = "";
+
+        int start = 0;
+        int end = values.size() - 1;
+        while (start <= end) {
+            int mid = (start + end) / 2;
+            if (values.get(mid).ts <= ts) {
+                res = values.get(mid).value;
+                start = mid + 1;
+            } else {
+                end = mid - 1;
+            }
+        }
+        return res;
+    } //TC: O(logn), where n is the number of timestamp in current key list
+}
+class Data {
+    int ts = 0;
+    String value = "";
+
+    Data(String value, int ts) {
+        this.ts = ts;
+        this.value = value;
+    }
+}
+
+/**
+ * Your TimeMap object will be instantiated and called as such:
+ * TimeMap obj = new TimeMap();
+ * obj.set(key,value,timestamp);
+ * String param_2 = obj.get(key,timestamp);
+ */