제출 #1041713

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1041713		abczz	Chorus (JOI23_chorus)	C++17	16 / 100	91 ms	20828 KiB

chorus

#include <iostream>
#include <algorithm>
#include <deque>
#include <vector>
#include <array>
#define ll long long

using namespace std;

ll n, k, dp[5000][5000];
vector <ll> A, B, nxA, ps;
string S;

ll C(ll l, ll r) {
  if (nxA[l] > A[r]) return 0;
  ll nx = max(l, nxA[l]), cnt = r-nx+1, cnt2 = max(0LL, l-nxA[l]);
  return ps[r]-(nx ? ps[nx-1] : 0)-cnt*B[l]-cnt*(cnt-1)/2-(r-l+1)*cnt2;
}

int main() {
  cin >> n >> k >> S;
  for (int i=0; i<2*n; ++i) {
    if (S[i] == 'A') {
      ps.push_back((ps.empty() ? 0 : ps.back()) + i);
      A.push_back(i);
    }
    else {
      B.push_back(i);
      nxA.push_back(A.size());
    }
  }
  for (int i=0; i<n; ++i) dp[i][0] = C(0, i);
  for (int x=1; x<k; ++x) {
    for (int i=0; i<n; ++i) {
      dp[i][x] = 1e18;
      ll optid = -1;
      for (int j=0; j<i; ++j) {
        if (dp[i][x] > dp[j][x-1] + C(j+1, i)) {
          dp[i][x] = dp[j][x-1] + C(j+1, i);
          optid = j;
        }
      }
    }
  }
  /*for (int x=0; x<k; ++x) {
    for (int i=0; i<n; ++i) {
      cout << dp[i][x] << " ";
    }
    cout << endl;
  }*/
  cout << dp[n-1][k-1] << '\n';
}

컴파일 시 표준 에러 (stderr) 메시지

chorus.cpp: In function 'int main()':
chorus.cpp:36:10: warning: variable 'optid' set but not used [-Wunused-but-set-variable]
   36 |       ll optid = -1;
      |          ^~~~~

• Subtask 1: 16 / 16
• Subtask 2: 0 / 24
• Subtask 3: 0 / 21
• Subtask 4: 0 / 26
• Subtask 5: 0 / 13