changhengliou

#define THROW_IF(arg, msg) \
  if (arg) throw runtime_error(msg);

using namespace std;

int main() {
  sockaddr_in addr{
          .sin_family = AF_INET,
          .sin_port = htons(PORT),
          .sin_addr = {.s_addr = INADDR_ANY},

changhengliou

int main() {
  int socketFd = socket(AF_INET, SOCK_STREAM, 0);
  assert(socketFd != 0);

  sockaddr_in addr{};
  socklen_t addrLen = sizeof(addr);

  int opt = 1;
  assert(setsockopt(socketFd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt)) == 0);

changhengliou

#include <vector>
#include <stack>
#include <iostream>

using namespace std;

int main() {
  vector<vector<int>> graph{
    {2, 3},
    {0},

changhengliou

#include <vector>

using namespace std;

void quick_sort(vector<int>& arr, int l, int r);
int quick_partition(vector<int>& arr, int l, int r);

int quick_partition(vector<int>& arr, int l, int r) {
  int pivot = (l + r) >> 1;
  swap(arr[pivot], arr[r]);

changhengliou

#include <vector>

using namespace std;

void heap_sort(vector<int>& arr);
void build_heap(vector<int>& arr, int n);
void heapify(vector<int>& arr, int n, int root);

void heap_sort(vector<int>& arr) {
  build_heap(arr, arr.size());

changhengliou

#include <vector>
#include <iostream>

using namespace std;

void merge_sort(vector<int>& arr);
void func(vector<int>& arr, int l, int r);
void merge(vector<int>& arr, int l, int m, int r);

void merge_sort(vector<int>& arr) {

changhengliou

#include <iostream>
#include <vector>
//                8
//            /   \   \
//          4      6    7
//        /   \      \
//      2      3      5
//    /
//  1
class FenwickTree {

changhengliou

class SegmentTreeNode {
public:
  int start;
  int end;
  int sum;
  SegmentTreeNode *left;
  SegmentTreeNode *right;
  SegmentTreeNode(int start, int end, int val)
      : start(start), end(end), sum(val), left(nullptr), right(nullptr) {}
  SegmentTreeNode(int start, int end, int val, SegmentTreeNode *left,

changhengliou

#include <cmath>
#include <iostream>
#include <vector>

using namespace std;

class SegmentTree {
private:
  // number of elements
  int _N;

changhengliou

#include <algorithm>
#include <iostream>
#include <vector>

using namespace std;

bool default_predicate(int a, int b) { return a > b; }

struct Heap {
private: