Submission #104261

#	Time	Username	Problem	Language	Result	Execution time	Memory
104261		arman_ferdous	Crayfish scrivener (IOI12_scrivener)	C++14	0 / 100	699 ms	87332 KiB

scrivener

// #include "grader.h"
#include <bits/stdc++.h>
using namespace std;

const int N = 1e6+10;
char c[N];
int lev[N];
int cur, freePtr;
int p[N][20], state[N], ptr;

void Init() {
	lev[0] = -1;
	memset(p,-1,sizeof p);
	c[0] = '?';
	cur = 0; freePtr = 1;
	state[0] = cur; ptr = 0;
}

void TypeLetter(char L) {
	int idx = freePtr++;
	p[idx][0] = cur;
	c[idx] = L, lev[idx] = lev[cur] + 1;
	cur = idx;

	for(int j = 1; j < 20; j++)
		if(p[cur][j-1] + 1)
			p[cur][j] = p[p[cur][j-1]][j-1];
	state[++ptr] = cur;
}

void UndoCommands(int U) {
	state[ptr+1] = state[max(0, ptr - U)];
	ptr++;
	cur = state[ptr];
}

char GetLetter(int P) {
	int tmp = cur, need = lev[cur] - P;
	for(int j = 19; j >= 0; j--) 
		if(need >= (1<<j)) {
			need -= (1<<j);
			cur = p[cur][j];
		}
	return c[cur];
}

Compilation message (stderr)

scrivener.cpp: In function 'char GetLetter(int)':
scrivener.cpp:38:6: warning: unused variable 'tmp' [-Wunused-variable]
  int tmp = cur, need = lev[cur] - P;
      ^~~

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