Submission #857198

#	Time	Username	Problem	Language	Result	Execution time	Memory
857198		lolismek	Brperm (RMI20_brperm)	C++14	50 / 100	2232 ms	262144 KiB

brperm

    #include "brperm.h"

    #include <iostream>

    using namespace std;

    const long long NMAX = 5e5;
    const long long LOGMAX = 19;

    const long long B = 29;
    const long long MOD = 1e9 + 7;

    long long dp[NMAX + 1][LOGMAX + 1][2];
    long long powB[NMAX + 1];

    long long h[NMAX + 1];

    void init(int n, const char s[]){
        powB[0] = 1;
        for(long long i = 1; i <= NMAX; i++){
            powB[i] = (1ll * powB[i - 1] * B) % MOD;
        }
        for(long long i = 1; i <= n; i++){
            h[i] = ((1ll * h[i - 1] * B) % MOD + (s[i - 1] - 'a' + 1)) % MOD;
        }
        long long pw = 1, pwind = 0;
        while(pw * 2 <= n){
            pw *= 2;
            pwind++;
        }

        for(long long k = pwind; k >= 0; k--){
            for(long long j = 0; (1 << j) <= n; j++){
                for(long long i = 1; i <= n; i++){
                    if(j == 0){
                        dp[i][j][k & 1] = (s[i - 1] - 'a' + 1);
                    }else{
                        if(i + ((1 << j) - 1) * (1 << k) <= n){
                            dp[i][j][k & 1] = ((1ll * dp[i][j - 1][(k + 1) & 1] * powB[(1 << (j - 1))]) % MOD + dp[i + (1 << k)][j - 1][(k + 1) & 1]) % MOD;
                        }
                    }
                }
            }
        }

        return;
    }

    int query(int i, int k){
        ++i;
        long long H1 = dp[i][k][0];
        long long H2 = (1ll * h[i + (1 << k) - 1] + MOD - ((1l * h[i - 1] * powB[(1 << k)]) % MOD)) % MOD;
        return (H1 == H2);
    }

• Subtask 1: 13 / 13
• Subtask 2: 37 / 37
• Subtask 3: 0 / 17
• Subtask 4: 0 / 33