Submission #120751

#	Time	Username	Problem	Language	Result	Execution time	Memory
120751		MAMBA	Crayfish scrivener (IOI12_scrivener)	C++17	0 / 100	3 ms	768 KiB

scrivener

#include <bits/stdc++.h>

using namespace std;

#define rep(i, j, k) for (int i = j; i < int(k); i++)

constexpr int N = 100 + 10;

struct node {
  node* par[20];
  char c = '\0';
  int deep = -1;
  node() { fill(par, par + 20, this); }
  node(char c_, node* p) {
    par[0] = p, c = c_;
    deep = p->deep + 1;
    rep(i, 1, 20) par[i] = par[i - 1]->par[i - 1];
  }
} state[N];

int now;
void Init() { now = 0; }

void TypeLetter(char L) { state[++now] = node(L, &state[now - 1]); }

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

char GetLetter(int P) {
  int goUp = state[now].deep - P;
  node* me = &state[now];
  rep(i, 0, 20) if (goUp >> i & 1) me = me->par[i];
  return me->c;
}

Compilation message (stderr)

scrivener.cpp: In function 'void TypeLetter(char)':
scrivener.cpp:24:33: warning: operation on 'now' may be undefined [-Wsequence-point]
 void TypeLetter(char L) { state[++now] = node(L, &state[now - 1]); }
                                 ^~~~~
scrivener.cpp: In function 'void UndoCommands(int)':
scrivener.cpp:26:34: warning: operation on 'now' may be undefined [-Wsequence-point]
 void UndoCommands(int U) { state[++now] = state[now - U - 1]; }
                                  ^~~~~

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