Submission #922761

#	Time	Username	Problem	Language	Result	Execution time	Memory
922761		vjudge1	JJOOII 2 (JOI20_ho_t2)	C++17	0 / 100	1 ms	464 KiB

ho_t2

#include <bits/stdc++.h>

using namespace std;
const int N = 2e5 + 12, MOD = 1e9 + 7;

typedef long long ll;

int n,k,A[N],B[N],C[N];
string s;
vector<int> a,b,c;
void test(){
    cin >> n >> k >> s;
    s = "#" + s;
    for(int i = 1;i <= n;i++){
        A[i] = A[i - 1];
        B[i] = B[i - 1];
        C[i] = C[i - 1];
        if(s[i] == 'J'){
            A[i]++;
            a.push_back(i);
        }else if(s[i] == 'O'){
            B[i]++;
            b.push_back(i);
        }else{
            C[i]++;
            c.push_back(i);
        }
    }
    if(min({(int)a.size(),(int)b.size(),(int)c.size()}) < k){
        cout << -1 << '\n';
        return;
    }
    int l = a[k - 1],r = c[(int)c.size() - k];
    if(B[r] - B[l] < k){
        cout << -1 << '\n';
        return;
    }
    int can_del = a[0] - 1 + (n - c.back());
    int cur_a = k - 1,cur_b = (int)c.size() - k;
    while(cur_a < (int)a.size() || cur_b >= 0){
        int newL = cur_a + 1,newR = cur_b -1;
//        cout << a[cur_a] << ' ' << c[cur_b] << ' ' << can_del << '\n';
        if(newR >= 0 && B[c[newR]] - B[a[cur_a]] >= k){
            cur_b = newR;
            can_del = a[cur_a - k + 1] - 1 + (n - c[cur_b + k - 1]);
        }else if(newL < (int)a.size() && B[c[cur_b]] - B[a[newL]] >= k){
            cur_a = newL;
            can_del = a[cur_a - k + 1] - 1 + (n - c[cur_b + k - 1]);
        }else break;
    }
    cout << n - k * 3 - can_del << '\n';
}
int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);
    int T = 1;
//    cin >> T;
    while (T--)
        test();
}

• Subtask 1: 0 / 1
• Subtask 2: 0 / 12
• Subtask 3: 0 / 87