Submission #114817

#	Time	Username	Problem	Language	Result	Execution time	Memory
114817		Shafin666	Crayfish scrivener (IOI12_scrivener)	C++98	34 / 100	43 ms	9848 KiB

scrivener

#include <cstdio>

const int maxn = 1e5+10;
int state[maxn], parent[maxn][25];
int depth[maxn]; char letter[maxn];
int stat = 0, command = 0;

void Init() {}

void TypeLetter(char L) {
    stat++, command++;
    state[command] = stat;
    letter[stat] = L;

    int par = state[command - 1];
    depth[stat] = depth[par] + 1;
    parent[stat][0] = par;
    letter[stat] = L;

    for(int i = 1; i <= 19; i++)
        parent[stat][i] = parent[parent[stat][i-1]][i-1];
}

void UndoCommands(int U) {
    command++;
    state[command] = state[command - U - 1];
}

char GetLetter(int P) {
    int cur = state[command];
    P = depth[cur] - P - 1;

    for(int i = 0; i <= 19; i++)
        if(P & (1 << i))
            cur = parent[cur][i];

    return letter[cur];
}

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