Submission #857199

#	Time	Username	Problem	Language	Result	Execution time	Memory
857199		lolismek	Brperm (RMI20_brperm)	C++14	50 / 100	106 ms	168836 KiB

brperm

#include "brperm.h"

#include <iostream>

using namespace std;

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

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

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

int h[NMAX + 1];

void init(int n, const char s[]){
    powB[0] = 1;
    for(int i = 1; i <= NMAX; i++){
        powB[i] = (1ll * powB[i - 1] * B) % MOD;
    }
    for(int i = 1; i <= n; i++){
        h[i] = ((1ll * h[i - 1] * B) % MOD + (s[i - 1] - 'a' + 1)) % MOD;
    }
    int pw = 1, pwind = 0;
    while(pw * 2 <= n){
        pw *= 2;
        pwind++;
    }
    for(int k = pwind; k >= 0; k--){
        for(int j = 0; (1 << j) <= n; j++){
            for(int 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;
    int H1 = dp[i][k][0];
    int 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