Added IntervalTree example

src/Common/examples/interval_tree.cpp

@@ -0,0 +1,120 @@
+#include <iomanip>
+#include <iostream>
+#include <map>
+#include <string>
+#include <set>
+#include <vector>
+
+#include <Common/randomSeed.h>
+#include <Common/Stopwatch.h>
+#include <Common/IntervalTree.h>
+
+using namespace DB;
+using Int64Interval = Interval<Int64>;
+
+struct CollectIntervalsCallback
+{
+    explicit CollectIntervalsCallback(std::set<Int64Interval> & result_intervals_)
+        : result_intervals(result_intervals_)
+    {
+    }
+
+    bool operator()(Int64Interval interval)
+    {
+        result_intervals.insert(interval);
+        return true;
+    }
+
+    std::set<Int64Interval> & result_intervals;
+};
+
+void findNecessaryIntervals(const std::vector<Int64Interval> & intervals, Int64 point, std::set<Int64Interval> & result_intervals)
+{
+    for (const auto & interval : intervals)
+    {
+        if (interval.contains(point))
+            result_intervals.insert(interval);
+    }
+}
+
+int main(int, char **)
+{
+    {
+        IntervalSet<Int64Interval> tree;
+
+        tree.emplace(Int64Interval(0, 5));
+        tree.emplace(Int64Interval(10, 15));
+
+        tree.construct();
+
+        for (const auto & interval : tree)
+        {
+            std::cout << "Interval left " << interval.left << " right " << interval.right << std::endl;
+        }
+    }
+    {
+        IntervalMap<Int64Interval, std::string> tree;
+
+        tree.emplace(Int64Interval(0, 5), "value1");
+        tree.emplace(Int64Interval(10, 15), "value2");
+
+        tree.construct();
+
+        for (const auto & [interval, value] : tree)
+        {
+            std::cout << "Interval left " << interval.left << " right " << interval.right;
+            std::cout << " value " << value << std::endl;
+        }
+    }
+    {
+        IntervalSet<Int64Interval> tree;
+        for (size_t i = 0; i < 5; ++i)
+        {
+            tree.emplace(Int64Interval(0, i));
+        }
+
+        tree.construct();
+
+        for (const auto & interval : tree)
+        {
+            std::cout << "Interval left " << interval.left << " right " << interval.right << std::endl;
+        }
+
+        for (Int64 i = 0; i < 5; ++i)
+        {
+            tree.find(i, [](auto & interval)
+            {
+                std::cout << "Interval left " << interval.left << " right " << interval.right << std::endl;
+                return true;
+            });
+        }
+    }
+    {
+        IntervalMap<Int64Interval, std::string> tree;
+        for (size_t i = 0; i < 5; ++i)
+        {
+            tree.emplace(Int64Interval(0, i), "Value " + std::to_string(i));
+        }
+
+        tree.construct();
+
+        for (const auto & [interval, value] : tree)
+        {
+            std::cout << "Interval left " << interval.left << " right " << interval.right;
+            std::cout << " value " << value << std::endl;
+        }
+
+        for (Int64 i = 0; i < 5; ++i)
+        {
+            tree.find(i, [](auto & interval, auto & value)
+            {
+                std::cout << "Interval left " << interval.left << " right " << interval.right;
+                std::cout << " value " << value << std::endl;
+
+                return true;
+            });
+        }
+    }
+
+    return 0;
+}