Submission #18494

#	Time	Username	Problem	Language	Result	Execution time	Memory
18494		eaststar	Crayfish scrivener (IOI12_scrivener)	C++14	100 / 100	774 ms	87988 KiB

scrivener

char c[1000010];
int a[1000010],lev[1000010],st[20][1000010],t;
void Init(){}
void TypeLetter(char L){
    int i;
    c[a[++t]=t]=L;
    lev[t]=lev[st[0][t]=a[t-1]]+1;
    for(i=1;i<20;++i)st[i][t]=st[i-1][st[i-1][t]];
}
void UndoCommands(int U){a[++t]=a[t-U-1];}
char GetLetter(int P){
    int i,x=a[t];
    for(i=20;i--;)if(lev[st[i][x]]>P)x=st[i][x];
    return c[x];
}

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