Submission #168586

#	Time	Username	Problem	Language	Result	Execution time	Memory
168586		tri	Crayfish scrivener (IOI12_scrivener)	C++11	34 / 100	1022 ms	97784 KiB

scrivener

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;

#define pb push_back
#define f first
#define s second

const int MAXN = 1e6 + 1e3;
const int LOGN = 21;

char lets[MAXN];
int L[MAXN], nLetI[MAXN], jmp[MAXN][LOGN];

void Init() {
    memset(lets, 0, sizeof(lets));
    memset(L, 0, sizeof(L));
    memset(nLetI, 0, sizeof(nLetI));
    memset(jmp, 0, sizeof(jmp));
}

int cI = 1;

inline void computeJump(int i) {
    for (int log = 1; log < LOGN; log++) {
        jmp[i][log] = jmp[jmp[i][log - 1]][log - 1];
    }
}

void TypeLetter(char cLet) {
    lets[cI] = cLet;
    L[cI] = L[cI - 1] + 1;

    if (lets[cI - 1] == 0) {
        nLetI[cI] = nLetI[cI - 1];
    } else {
        nLetI[cI] = cI - 1;
    }

    jmp[cI][0] = nLetI[cI];
    computeJump(cI);
    cI++;
}

void UndoCommands(int U) {
    L[cI] = L[cI - U - 1];

    if (lets[cI - U - 1] == 0) {
        nLetI[cI] = nLetI[cI - U - 1];
    } else {
        nLetI[cI] = cI - U - 1;
    }

    jmp[cI][0] = nLetI[cI];
    computeJump(cI);
    cI++;
}

char GetLetter(int P) {
    int nJ = L[cI - 1] - P - 1;
    int i = cI - 1;
    if (lets[i] == 0) {
        i = nLetI[i];
    }

    for (int log = LOGN - 1, jmps = 1 << log; log >= 0; log--, jmps /= 2) {
        if (jmps <= nJ) {
            i = jmp[i][log];
            nJ -= jmps;
        }
    }
    return lets[i];
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 22 / 22
• Subtask 4: 0 / 26
• Subtask 5: 0 / 40