Submission #206967

#	Time	Username	Problem	Language	Result	Execution time	Memory
206967		wiwiho	JJOOII 2 (JOI20_ho_t2)	C++14	100 / 100	38 ms	3136 KiB

ho_t2

//#define NDEBUG

#include <bits/stdc++.h>
#include <bits/extc++.h>

#define StarBurstStream ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define iter(a) a.begin(), a.end()
#define riter(a) a.rbegin(), a.rend()
#define lsort(a) sort(iter(a))
#define gsort(a) sort(riter(a))
#define mp(a, b) make_pair(a, b)
#define pb(a) push_back(a)
#define eb(a) emplace_back(a)
#define pf(a) push_front(a)
#define pob pop_back()
#define pof pop_front()
#define F first
#define S second
#define printv(a, b) {bool pvaspace=false; \
for(auto pva : a){ \
    if(pvaspace) b << " "; pvaspace=true;\
    b << pva;\
}\
b << "\n";}
#define pii pair<int, int>
#define pll pair<ll, ll>
#define tiii tuple<int, int, int>
#define mt make_tuple
#define gt(t, i) get<i>(t)
#define iceil(a, b) ((a) / (b) + !!((a) % (b)))

//#define TEST

typedef long long ll;
typedef unsigned long long ull;

using namespace std;
using namespace __gnu_pbds;

const ll MOD = 1000000007;
const ll MAX = 2147483647;

template<typename A, typename B>
ostream& operator<<(ostream& o, pair<A, B> p){
    return o << '(' << p.F << ',' << p.S << ')';
}


int main(){
    StarBurstStream

    int n, k;
    cin >> n >> k;
    string s;
    cin >> s;
    s = ' ' + s;

    vector<int> J(n + 1), O(n + 1), I(n + 1);
    for(int i = 1; i <= n; i++){
        if(s[i] == 'J') J[i]++;
        else if(s[i] == 'O') O[i]++;
        else I[i]++;
        J[i] += J[i - 1];
        O[i] += O[i - 1];
        I[i] += I[i - 1];
    }

    int ans = MAX;
    for(int i = 1; i <= n && J[n] - J[i - 1] >= k && O[n] - O[i - 1] >= k && I[n] - I[i - 1] >= k; i++){
        int l = lower_bound(iter(J), J[i - 1] + k) - J.begin();
        if(O[n] - O[l] < k || I[n] - I[l] < k) continue;
        int m = lower_bound(iter(O), O[l] + k) - O.begin();
        if(I[n] - I[m] < k) continue;
        int r = lower_bound(iter(I), I[m] + k) - I.begin();

        int now = 0;
        now += J[l] - J[i - 1] - k + O[l] - O[i - 1] + I[l] - I[i - 1];
        now += J[m] - J[l] + O[m] - O[l] - k + I[m] - I[l];
        now += J[r] - J[m] + O[r] - O[m] + I[r] - I[m] - k;
        ans = min(ans, now);
    }

    if(ans == MAX) ans = -1;
    cout << ans << "\n";

    return 0;
}

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