/ SeriousOJ /

Record Detail

Accepted


  
# Status Time Cost Memory Cost
#1 Accepted 1ms 532.0 KiB
#2 Accepted 1ms 532.0 KiB
#3 Accepted 1ms 408.0 KiB
#4 Accepted 1ms 484.0 KiB
#5 Accepted 1ms 532.0 KiB
#6 Accepted 1ms 532.0 KiB
#7 Accepted 1ms 532.0 KiB
#8 Accepted 1ms 532.0 KiB
#9 Accepted 1ms 532.0 KiB
#10 Accepted 1ms 428.0 KiB
#11 Accepted 1ms 424.0 KiB
#12 Accepted 1ms 456.0 KiB
#13 Accepted 1ms 536.0 KiB
#14 Accepted 1ms 532.0 KiB
#15 Accepted 1ms 332.0 KiB
#16 Accepted 1ms 536.0 KiB
#17 Accepted 1ms 532.0 KiB
#18 Accepted 1ms 320.0 KiB
#19 Accepted 1ms 712.0 KiB
#20 Accepted 1ms 532.0 KiB
#21 Accepted 1ms 532.0 KiB
#22 Accepted 1ms 488.0 KiB
#23 Accepted 1ms 496.0 KiB
#24 Accepted 2ms 532.0 KiB
#25 Accepted 2ms 536.0 KiB
#26 Accepted 4ms 532.0 KiB
#27 Accepted 4ms 532.0 KiB
#28 Accepted 4ms 532.0 KiB
#29 Accepted 4ms 532.0 KiB
#30 Accepted 4ms 532.0 KiB
#31 Accepted 4ms 532.0 KiB
#32 Accepted 4ms 324.0 KiB
#33 Accepted 4ms 536.0 KiB
#34 Accepted 4ms 440.0 KiB
#35 Accepted 4ms 532.0 KiB
#36 Accepted 4ms 532.0 KiB
#37 Accepted 4ms 532.0 KiB
#38 Accepted 4ms 532.0 KiB
#39 Accepted 4ms 532.0 KiB
#40 Accepted 4ms 532.0 KiB
#41 Accepted 5ms 484.0 KiB
#42 Accepted 5ms 532.0 KiB
#43 Accepted 5ms 584.0 KiB
#44 Accepted 5ms 532.0 KiB
#45 Accepted 5ms 532.0 KiB
#46 Accepted 5ms 532.0 KiB
#47 Accepted 5ms 580.0 KiB
#48 Accepted 5ms 532.0 KiB
#49 Accepted 5ms 532.0 KiB
#50 Accepted 5ms 532.0 KiB
#51 Accepted 5ms 428.0 KiB
#52 Accepted 5ms 532.0 KiB
#53 Accepted 5ms 532.0 KiB
#54 Accepted 5ms 532.0 KiB
#55 Accepted 5ms 536.0 KiB
#56 Accepted 5ms 532.0 KiB
#57 Accepted 5ms 580.0 KiB
#58 Accepted 5ms 532.0 KiB
#59 Accepted 5ms 532.0 KiB
#60 Accepted 5ms 532.0 KiB
#61 Accepted 9ms 532.0 KiB
#62 Accepted 7ms 532.0 KiB
#63 Accepted 7ms 532.0 KiB
#64 Accepted 9ms 588.0 KiB
#65 Accepted 9ms 584.0 KiB
#66 Accepted 7ms 536.0 KiB
#67 Accepted 7ms 460.0 KiB
#68 Accepted 7ms 532.0 KiB
#69 Accepted 7ms 532.0 KiB
#70 Accepted 7ms 532.0 KiB
#71 Accepted 14ms 656.0 KiB
#72 Accepted 9ms 736.0 KiB
#73 Accepted 10ms 704.0 KiB
#74 Accepted 13ms 656.0 KiB
#75 Accepted 13ms 724.0 KiB
#76 Accepted 9ms 656.0 KiB
#77 Accepted 9ms 704.0 KiB
#78 Accepted 10ms 648.0 KiB
#79 Accepted 9ms 704.0 KiB
#80 Accepted 9ms 728.0 KiB
#81 Accepted 16ms 788.0 KiB
#82 Accepted 10ms 788.0 KiB
#83 Accepted 11ms 788.0 KiB
#84 Accepted 15ms 788.0 KiB
#85 Accepted 13ms 788.0 KiB
#86 Accepted 5ms 788.0 KiB
#87 Accepted 5ms 792.0 KiB
#88 Accepted 6ms 728.0 KiB
#89 Accepted 5ms 788.0 KiB
#90 Accepted 5ms 788.0 KiB
#91 Accepted 44ms 2.336 MiB
#92 Accepted 18ms 2.27 MiB
#93 Accepted 21ms 2.316 MiB
#94 Accepted 31ms 2.188 MiB
#95 Accepted 37ms 2.184 MiB
#96 Accepted 18ms 2.188 MiB
#97 Accepted 19ms 2.27 MiB
#98 Accepted 32ms 2.184 MiB
#99 Accepted 20ms 2.188 MiB
#100 Accepted 18ms 2.34 MiB

Code

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <map>
#include <set>
//#include <queue>
//#include <numeric>
#include <cassert>

using namespace std;

#ifdef LOCAL_DEBUG
#include <local_debug.h>
#define DEBUG(...) DBG2::cprint(#__VA_ARGS__, __LINE__, __VA_ARGS__)
#else
#define DEBUG(...)
#endif

#define SZ(a) int((a).size())
#define REP(i,n) for(int i=0,_n=(n);i<_n;++i)
#define FOR(i,a,b) for(int i=(a),_b=(b);i<=_b;++i)

using llong = long long;
using VI = vector<int>;
using VVI = vector<VI>;
using II = pair<int,int>;

class SegmentTree {
   int N;
   vector<int> T;

   void build() {
      for (int i = N - 1; i > 0; --i)
         T[i] = T[2*i] + T[2*i+1];
   }
public:
   SegmentTree(int _N) {
      for (N = 1; N < _N; N *= 2);
      T.assign(N*2, 0);
      build();
   }

   void update(int p, int value) {
      int i = p + N;
      T[i] += value;
      for (i /= 2; i > 0; i /= 2)
         T[i] = T[2*i] + T[2*i+1];
   }

   int query(int L, int R) const {
      int resL = 0, resR = 0;
      for (int l = L + N, r = R + N; l <= r; l /= 2, r /= 2) {
         if (1 == (l & 1)) resL = resL + T[l++];
         if (0 == (r & 1)) resR = T[r--] + resR;
      }
      return resL + resR;
   }
};

int solve(int N, VI A) {
   vector<bool> special(N, false);

   {
      SegmentTree st(N + 1);
      for (int i = 0; i < N; i++) {
         int a = A[i];
         int cnt = st.query(0, a);
         if (cnt >= a)
            special[i] = true;
         st.update(a, 1);
      }
   }

   {
      SegmentTree st(N + 1);
      for (int i = N-1; i >= 0; i--) {
         int a = A[i];
         int cnt = st.query(a, N);
         if (cnt >= a)
            special[i] = true;
         st.update(a, 1);
      }
   }

   int res = count(special.begin(), special.end(), true);
   return res;
}

int main(int argc, char* argv[]) {
   ios_base::sync_with_stdio(false); 
   cin.tie(nullptr);

   int N;
   cin >> N;
   VI A(N);
   REP(i, N)
      cin >> A[i];
   int res = solve(N, A);
   cout << res << '\n';

   return 0;
}

Information

Submit By
Type
Submission
Problem
P1184 The Curious Kid and the Number Game
Contest
Brain Booster #9
Language
C++17 (G++ 13.2.0)
Submit At
2025-04-06 16:07:35
Judged At
2025-04-06 16:07:35
Judged By
Score
100
Total Time
44ms
Peak Memory
2.34 MiB