fix(post): fetch code lazily

public/code/algorithms/extrema-circular-buffer/monotonic.cpp

@@ -0,0 +1,65 @@
+#include <deque>
+#include <stdexcept>
+#include <utility>
+
+class ExtremaCircularBuffer {
+public:
+  explicit ExtremaCircularBuffer(size_t capacity) : capacity(capacity) {}
+
+  void push_back(double value) {
+    if (prices.size() == capacity) {
+      double front_value = prices.front();
+      pop_max(front_value);
+      prices.pop_front();
+    }
+
+    prices.push_back(value);
+    push_max(value);
+  }
+
+  void pop_front() {
+    if (prices.empty()) {
+      throw std::out_of_range("Cannot pop_front() from empty buffer");
+    }
+
+    double front_value = prices.front();
+    pop_max(front_value);
+    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 maxs.front().first;
+  }
+
+private:
+  void push_max(double value) {
+    size_t popped = 0;
+
+    while (!maxs.empty() && maxs.back().first < value) {
+      popped += maxs.back().second + 1;
+      maxs.pop_back();
+    }
+
+    maxs.emplace_back(value, popped);
+  }
+
+  void pop_max(double value) {
+    size_t popped = maxs.front().second;
+
+    if (popped == 0) {
+      maxs.pop_front();
+    } else {
+      --maxs.front().second;
+    }
+  }
+
+  std::deque<double> prices;
+  std::deque<std::pair<double, size_t>> maxs;
+  size_t capacity;
+};