Problem_STOII_0042_RecentCounter.cc

#include <iostream>
#include <vector>

using namespace std;

// seem as leetcode 0933
// https://leetcode-cn.com/problems/number-of-recent-calls/
// see at Problem_0933_RecentCounter.cc
class RecentCounter
{
 private:
  vector<int> arr;

 public:
  RecentCounter() {}

  int ping(int t)
  {
    arr.push_back(t);
    int idx = -1;
    int n = arr.size();
    int left = 0;
    int right = n - 1;
    int target = t - 3000;
    while (left <= right)
    {
      int mid = (right - left) / 2 + left;
      if (target <= arr[mid])
      {
        idx = mid;
        right = mid - 1;
      }
      else
      {
        left = mid + 1;
      }
    }
    return arr.size() - idx;
  }
};

/**
 * Your RecentCounter object will be instantiated and called as such:
 * RecentCounter* obj = new RecentCounter();
 * int param_1 = obj->ping(t);
 */