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//1 class MapSum { Map map ; /** Initialize your data structure here. */ public MapSum() { map = new HashMap<>(); } public void insert(String key, int val) { map.put(key, val); } public int sum(String prefix) { int sum = 0; for(String s : map.keySet()) { if(s.startsWith(prefix)) sum += map.get(s); } return sum; } } /** * Your MapSum object will be instantiated and called as such: * MapSum obj = new MapSum(); * obj.insert(key,val); * int param_2 = obj.sum(prefix); */ // 2