Submission #130264

#	Time	Username	Problem	Language	Result	Execution time	Memory
130264		khulegub	Crayfish scrivener (IOI12_scrivener)	C++14	100 / 100	638 ms	73052 KiB

scrivener

#include <bits/stdc++.h>
#define pb push_back
#define xx first
#define yy second
#define mp make_pair
using namespace std;

/*
IM RETARDED, JUST SO YOU KNOW LOL.
*/

/*
 
#############################################
# x X x _ P u $ $ y S l a y e r 6 9 _ x X x #
#############################################
 
*/
 
/*
Check array size
Check IO
*/
int sz;
int curr;
vector<pair<char, int> > s; //storing chars and ranks
int node_par[1000005][20]; //nodes parents
int par[1000005]; //cmds parents
vector<int> pos; //storing each cmd's position in "s"
void Init() {
	s.pb(mp('#', 0));
	sz = 0;
	curr = 0; //current cmd is 0
	pos.pb(0); //cmd 0 s position of node is 0
	node_par[0][0] = 0;
	par[0] = 0;
}
void TypeLetter(char L) {
	s.pb(mp(L, s[ pos[curr] ].yy + 1)); //typing letter means new node
	sz++;
	node_par[sz][0] = pos[curr];
	for (int i = 1; i <= 20; i++){
		node_par[sz][i] = node_par[ node_par[sz][i - 1] ][i - 1];
	}
	pos.pb(sz);
	par[++curr] = curr;
}
void UndoCommands(int U) {
	pos.pb(pos[curr - U]);
	par[++curr] = curr - U;
}
char GetLetter(int P) {
	P++;
	int tmp = pos[curr];
	int j = s[tmp].yy - P;
	for (int i = 0; i <= 20; i++ ){
		if ( (j & (1 << i))){
			tmp = node_par[tmp][i];
		}
	}
	return s[tmp].xx;
}

Compilation message (stderr)

scrivener.cpp: In function 'void TypeLetter(char)':
scrivener.cpp:46:6: warning: operation on 'curr' may be undefined [-Wsequence-point]
  par[++curr] = curr;
      ^~~~~~
scrivener.cpp: In function 'void UndoCommands(int)':
scrivener.cpp:50:6: warning: operation on 'curr' may be undefined [-Wsequence-point]
  par[++curr] = curr - U;
      ^~~~~~
scrivener.cpp: In function 'void TypeLetter(char)':
scrivener.cpp:43:19: warning: iteration 19 invokes undefined behavior [-Waggressive-loop-optimizations]
   node_par[sz][i] = node_par[ node_par[sz][i - 1] ][i - 1];
   ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
scrivener.cpp:42:20: note: within this loop
  for (int i = 1; i <= 20; i++){
                  ~~^~~~~

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