Submission #247085

#	Time	Username	Problem	Language	Result	Execution time	Memory
247085		lakshith_	Crayfish scrivener (IOI12_scrivener)	C++14	100 / 100	751 ms	90616 KiB

scrivener

char ops[1000005];
int prev[1000005][20], size[1000005], sz;
int go[1000005];

void Init(){
  sz = 1;
}

void TypeLetter(char L){
  int p = sz;
  go[p] = p;
  ops[p] = L;
  if(p)prev[p][0]=go[p-1];
  for(int i=1;prev[p][i-1];i++)
    prev[p][i] = prev[prev[p][i-1]][i-1];
  size[p]=size[go[p-1]]+1;
  sz++;
}

void UndoCommands(int U){
  go[sz]=go[sz-U-1];
  sz++;
}

char GetLetter(int P){
  int pos = go[sz-1];
  int o = P+1;
  for(int i=19;i>=0;i--)
    if(size[prev[pos][i]]>=o)
      pos = prev[pos][i];
  return ops[pos];
}

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