added randomizedset

CMakeLists.txt

@@ -15,3 +15,4 @@ add_subdirectory(maxprofit2)
 add_subdirectory(canJump)
 add_subdirectory(jump)
 add_subdirectory(hindex)
+add_subdirectory(randomizedset)

Makefile

@@ -1,4 +1,4 @@
-SUBDIRS := canJump jump majorityelement maxprofit maxprofit2 rmdupfromsortedarray rmdupfromsortedarray2 rotate twopointers hindex
+SUBDIRS := canJump jump majorityelement maxprofit maxprofit2 rmdupfromsortedarray rmdupfromsortedarray2 rotate twopointers hindex randomizedset
 
 all: $(SUBDIRS)
 

meson.build

@@ -9,3 +9,4 @@ subdir('maxprofit2')
 subdir('canJump')
 subdir('jump')
 subdir('hindex')
+subdir('randomizedset')

randomizedset/CMakeLists.txt

@@ -0,0 +1,6 @@
+FILE(GLOB_RECURSE SOURCES src/*.cpp)
+
+add_executable(
+    randomizedset
+    ${SOURCES}
+)

randomizedset/Makefile

@@ -0,0 +1,17 @@
+CXX = g++
+CFLAGS = -Wall -g
+SRCS = $(wildcard src/*/*.cpp src/*.cpp)
+OBJS = $(SRCS:.cpp=.o)
+TARGET = randomizedset
+CROSS_COMPILE =
+
+all: $(TARGET)
+
+$(TARGET): $(OBJS)
+	$(CROSS_COMPILE)$(CXX) $(LDFLAGS) $^ -o $@ $(LIBS)
+
+%.o: %.cpp
+	$(CROSS_COMPILE)$(CXX) $(CFLAGS) $(INCLUDES) -c $< -o $@
+
+clean:
+	rm -f $(OBJS) $(TARGET)

randomizedset/meson.build

@@ -0,0 +1 @@
+executable('randomizedset', 'src/main.cpp', install: true)

randomizedset/src/main.cpp

@@ -0,0 +1,35 @@
+#include <cassert>
+#include <iostream>
+#include "randomizedset.hpp"
+
+int main() {
+  RandomizedSet *randomizedSet = new RandomizedSet();
+  bool res = randomizedSet->insert(1);
+  std::cout << res << std::endl;
+  assert(res == true);
+
+  res = randomizedSet->remove(2);
+  std::cout << res << std::endl;
+  assert(res == false);
+
+  res = randomizedSet->insert(2);
+  std::cout << res << std::endl;
+  assert(res == true);
+
+  int ires = randomizedSet->getRandom();
+  std::cout << ires << std::endl;  // Функция getRandom() должна возвращать
+                                   // случайным образом либо 1, либо 2.
+
+  res = randomizedSet->remove(1);
+  std::cout << res << std::endl;
+  assert(res == true);
+
+  res = randomizedSet->insert(2);
+  std::cout << res << std::endl;
+  assert(res == false);
+
+  ires = randomizedSet->getRandom();
+  std::cout << ires << std::endl;
+  assert(ires == 2);
+  return 0;
+}

randomizedset/src/randomizedset.hpp

@@ -0,0 +1,38 @@
+#include <cstdlib>
+#include <ctime>
+#include <unordered_map>
+#include <vector>
+
+class RandomizedSet {
+ public:
+  RandomizedSet() {
+    srand(time(nullptr));
+  }
+
+  bool insert(int val) {
+    if (map.find(val) != map.end()) return false;
+    map[val] = list.size();
+    list.push_back(val);
+    return true;
+  }
+
+  bool remove(int val) {
+    auto it = map.find(val);
+    if (it == map.end()) return false;
+    int idx = it->second;
+    int lastVal = list.back();
+    list[idx] = lastVal;
+    map[lastVal] = idx;
+    list.pop_back();
+    map.erase(it);
+    return true;
+  }
+
+  int getRandom() {
+    return list[rand() % list.size()];
+  }
+
+ private:
+  std::vector<int> list;
+  std::unordered_map<int, int> map;
+};