Submission #819259

#	Time	Username	Problem	Language	Result	Execution time	Memory
819259		Arpenteur	JJOOII 2 (JOI20_ho_t2)	C++17	100 / 100	4 ms	2012 KiB

ho_t2

#include <iostream>
#include <vector>
#include <limits.h>
using namespace std;
const char el = '\n';

int main() {
  ios_base::sync_with_stdio(false), cin.tie(nullptr);
  int n, k; cin >> n >> k;
  string s; cin >> s;
  vector<int> J, O, I;
  for(int i=0; i<n; i++)
    switch(s[i]) {
      case 'J': J.push_back(i); break;
      case 'O': O.push_back(i); break;
      case 'I': I.push_back(i); break;
    }
  int ij = 0, io = 0, ii = 0, jsz = J.size(), osz = O.size(), isz = I.size();
  int endj, endo, sol = INT_MAX;
  auto print_sol = [&] () {
    if(sol==INT_MAX) cout << -1 << el;
    else cout << sol << el;
    return 0;
  };
  while(true) {
    if(ij+k-1>=jsz) return print_sol();
    endj = J[ij+k-1];
    while(io<osz && O[io]<=endj) io++;
    if(io+k-1>=osz) return print_sol();
    endo = O[io+k-1];
    while(ii<isz && I[ii]<=endo) ii++;
    if(ii+k-1>=isz) return print_sol();
    sol = min(sol, I[ii+k-1]-J[ij]+1-k-k-k);
    ij++;
  }
  return print_sol();
}

• Subtask 1: 1 / 1
• Subtask 2: 12 / 12
• Subtask 3: 87 / 87