solution of Time Based Key-Value Store (based on hashmap and binary search)

Author: emikhalev

leetcode/time_based_key_value_store-solution-1-map-binarysearch.go

@@ -0,0 +1,65 @@
+// https://leetcode.com/problems/time-based-key-value-store
+package main
+
+type TimeMap struct {
+data map[string][]timeMapRecord
+}
+
+type timeMapRecord struct {
+ts int
+val string
+}
+
+/** Initialize your data structure here. */
+func Constructor() TimeMap {
+return TimeMap{
+data: make(map[string][]timeMapRecord),
+}
+}
+
+func (this *TimeMap) Set(key string, value string, timestamp int) {
+d, ok := this.data[key]
+if !ok {
+d = make([]timeMapRecord, 0)
+}
+d = append(d, timeMapRecord{
+ts: timestamp,
+val: value,
+})
+this.data[key] = d
+}
+
+func (this *TimeMap) Get(key string, timestamp int) string {
+d, ok := this.data[key]
+if !ok {
+return ""
+}
+// binary search
+l := 0
+r := len(d) - 1
+idx := -1
+for l <= r {
+m := (l + r) / 2
+if d[m].ts < timestamp {
+l = m + 1
+idx = m
+continue
+} else if d[m].ts > timestamp {
+r = r - 1
+} else {
+idx = m
+break
+}
+}
+if idx == -1 {
+return ""
+}
+return d[idx].val
+}
+
+/**
+ * Your TimeMap object will be instantiated and called as such:
+ * obj := Constructor();
+ * obj.Set(key,value,timestamp);
+ * param_2 := obj.Get(key,timestamp);
+ */