There are n (id, value) pairs, where id is an integer between 1 and n and value is a string. No two pairs have the same id.
Design a stream that takes the n pairs in an arbitrary order, and returns the values over several calls in increasing order of their ids.
Implement the OrderedStream class:
OrderedStream(int n) Constructs the stream to take n values and sets a current ptr to 1. String[] insert(int id, String value) Stores the new (id, value) pair in the stream. After storing the pair: If the stream has stored a pair with id = ptr, then find the longest contiguous incrementing sequence of ids starting with id = ptr and return a list of the values associated with those ids in order. Then, update ptr to the last id + 1. Otherwise, return an empty list.
Example:
Input ["OrderedStream", "insert", "insert", "insert", "insert", "insert"] [[5], [3, "ccccc"], [1, "aaaaa"], [2, "bbbbb"], [5, "eeeee"], [4, "ddddd"]] Output [null, [], ["aaaaa"], ["bbbbb", "ccccc"], [], ["ddddd", "eeeee"]]
Explanation OrderedStream os= new OrderedStream(5); os.insert(3, "ccccc"); // Inserts (3, "ccccc"), returns []. os.insert(1, "aaaaa"); // Inserts (1, "aaaaa"), returns ["aaaaa"]. os.insert(2, "bbbbb"); // Inserts (2, "bbbbb"), returns ["bbbbb", "ccccc"]. os.insert(5, "eeeee"); // Inserts (5, "eeeee"), returns []. os.insert(4, "ddddd"); // Inserts (4, "ddddd"), returns ["ddddd", "eeeee"].
Constraints:
1 <= n <= 1000 1 <= id <= n value.length == 5 value consists only of lowercase letters. Each call to insert will have a unique id. Exactly n calls will be made to insert.
public class OrderedStream {
string[] strArr;
int ptr = 0;
public OrderedStream(int n) {
strArr = new string[n];
}
public IList<string> Insert(int id, string value) {
id = id-1;
strArr[id]=value;
var result = new List<string>();
if(ptr==id){
while(ptr < strArr.Length && strArr[ptr]!=null){
result.Add(strArr[ptr]);
ptr++;
}
}
return result;
}
}
/**
* Your OrderedStream object will be instantiated and called as such:
* OrderedStream obj = new OrderedStream(n);
* IList<string> param_1 = obj.Insert(id,value);
*/Time Complexity: O(n)
Space Complexity: O(n)
