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Problem · Array

Chronological Sliding-Window Request Counter

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Problem statement

Process chronological operations describing request arrivals and count queries.

  • ["ADD", t] records one request at integer timestamp t.
  • ["COUNT", t, n] asks how many prior ADD timestamps lie in the inclusive interval [t - 60 * n, t].

Operation timestamps are nondecreasing. Return one integer for each COUNT, in operation order. A request exactly at either boundary is included.

Function

processRequestOperations(operations: String[][]) → int[]

Examples

Example 1

operations = [["ADD","10"],["ADD","70"],["COUNT","70","1"],["COUNT","71","1"]]return = [2,1]

The first query includes timestamps 10 and 70. The second window starts at 11, excluding timestamp 10.

Example 2

operations = [["COUNT","0","5"],["ADD","0"],["COUNT","0","1"]]return = [0,1]

The first query has no prior requests; the second includes the request at its upper boundary.

Constraints

  • 1 <= operations.length <= 200000.
  • 0 <= t <= 1000000000.
  • 1 <= n <= 1000000000.
  • All rows are valid and timestamps are nondecreasing.
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public int[] processRequestOperations(String[][] operations) {
    // Write your code here.
}
operations[["ADD","10"],["ADD","70"],["COUNT","70","1"],["COUNT","71","1"]]
expected[2,1]
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