barrettruth.com/public/code/algorithms/extrema-circular-buffer/map.cpp

56 lines
1.2 KiB
C++

#include <deque>
#include <map>
#include <stdexcept>
class ExtremaCircularBuffer {
public:
ExtremaCircularBuffer(size_t capacity) : capacity(capacity) {}
void push_back(double value) {
if (prices.size() == capacity) {
double front = prices.front();
if (--sorted_prices[front] == 0)
sorted_prices.erase(front);
prices.pop_front();
}
prices.push_back(value);
++sorted_prices[value];
}
void pop_front() {
if (prices.empty()) {
throw std::out_of_range("Cannot pop_front() from empty buffer");
}
double front = prices.front();
if (--sorted_prices[front] == 0)
sorted_prices.erase(front);
prices.pop_front();
}
size_t size() const { return prices.size(); }
double get_max() const {
if (prices.empty()) {
throw std::out_of_range("Cannot find max() of empty buffer");
}
return sorted_prices.rbegin()->first;
}
double get_min() const {
if (prices.empty()) {
throw std::out_of_range("Cannot find min() of empty buffer");
}
return sorted_prices.begin()->first;
}
private:
std::deque<double> prices;
std::map<double, size_t> sorted_prices;
size_t capacity;
};