Submission #956473

#	Time	Username	Problem	Language	Result	Execution time	Memory
956473		steveonalex	JJOOII 2 (JOI20_ho_t2)	C++17	100 / 100	18 ms	43240 KiB

ho_t2

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T& container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

const int N = 2e5 + 69, LOG_N = 18;
const int INF = 1e9 + 69;
int nxt[3][LOG_N][N];

int lift(int j, int i, int d){
    for(int t = 0; t < LOG_N; ++t) if (GETBIT(d, t)) 
        i = nxt[j][t][i];
    return i;
}

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int n, k; cin >> n >> k;
    string s; cin >> s;
    for(int j = 0; j<3; ++j) nxt[j][0][n] = n;
    for(int i = n-1; i>=0; --i){
        for(int j = 0; j < 3; ++j) nxt[j][0][i] = nxt[j][0][i+1];
        if (i < n - 1){
            if (s[i + 1] == 'J') nxt[0][0][i] = i + 1;
            else if (s[i+1] == 'O') nxt[1][0][i] = i + 1;
            else nxt[2][0][i] = i + 1;
        }
    }


    for(int j = 0; j < 3; ++j){
        for(int t = 1; t < LOG_N; ++ t){
            for(int i = 0; i<=n; ++i) 
                nxt[j][t][i] = nxt[j][t-1][nxt[j][t-1][i]];
        }
    }

    int ans = INF;
    for(int i = 0; i<n; ++i) if (s[i] == 'J'){
        int j = i;
        j = lift(0, j, k-1);
        j = lift(1, j, k);
        j = lift(2, j, k);
        if (j == n) break;
        minimize(ans, j - i + 1 - 3 * k);
    }
    if (ans == INF) cout << -1 << "\n";
    else cout << ans << "\n";

    return 0;
}

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