이 제출은 이전 버전의 oj.uz에서 채점하였습니다. 현재는 제출 당시와는 다른 서버에서 채점을 하기 때문에, 다시 제출하면 결과가 달라질 수도 있습니다.
//#include <atcoder/maxflow.hpp>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
 
#include <iostream>
#include <map>
#include <list>
#include <set>
#include <algorithm>
#include <vector>
#include <string>
#include <functional>
#include <queue>
#include <deque>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <cmath>
#include <iterator>
#include <random>
#include <chrono>
#include <complex>
#include <bitset>
#include <fstream>
 
 
#define forr(i,start,count) for (int i = (start); i < (start)+(count); ++i)
#define set_map_includes(set, elt) (set.find((elt)) != set.end())
#define readint(i) int i; cin >> i
#define readll(i) ll i; cin >> i
#define readdouble(i) double i; cin >> i
#define readstring(s) string s; cin >> s
typedef long long ll;
 
//using namespace __gnu_pbds;
//using namespace atcoder;
using namespace std;
const ll modd = (1000LL * 1000LL * 1000LL + 7LL);
//const ll modd = 998244353;
template<class T>
class SegmentTree2 {
    public:
     
      SegmentTree2(const vector<T>& data, function<T(T,T)> f_, T zero_value = 0) : zv(zero_value), f(f_) {   
          Initialize(data);
      }
      SegmentTree2(int n, function<T(T,T)> f_, T zero_value = 0) : zv(zero_value), f(f_) {
          vector<T> temp(n, zv);
          Initialize(temp);
      }
      T operator[](int i) {
          return tree[B+i];
      }
      T GetEvaluation(int L, int R) {   // "min/max" on interval [L,R); 0-based indexing, as usual
        if (R<=L) {  return zv;  }
        return GetEvaluationHelper(L, R, 0, B, 1);
      }
      void SetVal(int i, T val) {
			tree[B+i] = val;
			for(int j = (B + i) / 2; j >= 1; j /= 2) {
				tree[j] = f(tree[2*j], tree[2*j+1]);
			}
      }
      private:
        vector<T> tree;
        int B;  // power of two greater than size of input data
        T zv;
        function<T(T,T)> f;
        void Initialize(const vector<T>& data) {
    	  B = 1;
          while(B < data.size()) {B *= 2;  }
          tree = std::move(vector<T>(2*B, zv));
          copy(data.begin(), data.end(), next(tree.begin(), B));
          for(int i = B - 1; i >= 1; --i) {
  	  	     tree[i] = f(tree[2*i], tree[2*i+1]);
          }
        }
      T GetEvaluationHelper(int L, int R, int start, int length, int tree_index) {
          if (L==R) {  return zv; }
          if ((L==start) && (R==start+length)) {   return tree[tree_index];  }
          int midpoint = start + length/2;
          T left_ = zv, right_ = zv;
          if (L<=min(midpoint,R)) {
            left_ = GetEvaluationHelper(L, min(midpoint,R), start, length/2, 2*tree_index);
          }
          if (max(midpoint,L)<=R) {
            right_ = GetEvaluationHelper(max(midpoint,L), R, midpoint, length/2, 2*tree_index+1);
          }
          return f(left_, right_);
      }
};
int main(int argc, char *argv[])   {
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
    uniform_int_distribution<int> rand_gen(0, modd);   // rand_gen(rng) gets the rand no
    ios_base::sync_with_stdio(false);
    cin.tie(0);
 
    cout.precision(12);
//    readint(test_cases);
    int test_cases = 1;
    forr(t, 1, test_cases) {
        readint(n); readint(d);
        vector<int> a;
        forr(i,0,n) {
            readint(aa); a.push_back(aa);
        }
        int res = 0;
        if (d==1) {
            res = 1;
            deque<int> vals;
            vals.push_back(a.back());
            for(int i = n-2; i >= 0; --i) {
                while ((!vals.empty()) && (vals.front()<=a[i])) {  vals.pop_front();  }
                vals.push_front(a[i]);
                res = max(res, (int)vals.size());
            }
        }
        if (d==n) {
            map<int,vector<int>> freq;
            forr(i,0,n) {
                freq[a[i]].push_back(i);
            }
            SegmentTree2<int> so_far(vector<int>(n, 0), [](int x, int y){ return max(x,y); }, 0);
            for(auto x : freq) {
                for(int i = x.second.size()-1; i >= 0; --i)  {
                    res = max(res, 1+so_far.GetEvaluation(0, x.second[i]));
                    so_far.SetVal(x.second[i], res);
                }
            }
        }
        cout << res << endl;
    }
    return 0;
}
컴파일 시 표준 에러 (stderr) 메시지
Main.cpp: In instantiation of 'void SegmentTree2<T>::Initialize(const std::vector<_Tp>&) [with T = int]':
Main.cpp:51:11:   required from 'SegmentTree2<T>::SegmentTree2(const std::vector<_Tp>&, std::function<T(T, T)>, T) [with T = int]'
Main.cpp:146:96:   required from here
Main.cpp:84:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |           while(B < data.size()) {B *= 2;  }
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