Submission #933257

#	Time	Username	Problem	Language	Result	Execution time	Memory
933257		SmuggingSpun	Cave (IOI13_cave)	C++14	100 / 100	656 ms	1108 KiB

cave

#include "cave.h"
#include<bits/stdc++.h>
using namespace std;
const int lim = 5e3 + 5;
int S[lim], D[lim];
bitset<lim>vis;
void exploreCave(int n){
	vis.reset();
	for(int i = 0; i < n; i++){
		for(int j = 0; j < n; j++){
			if(!vis.test(j)){
				S[j] = 0;
			}
		}
		if(tryCombination(S) != i){
			for(int j = 0; j < n; j++){
				if(!vis.test(j)){
					S[j] = 1;
				}
			}
		}
		int low = 0, high = n - 1, ans;
		while(low <= high){
			int mid = (low + high) >> 1;
			for(int j = mid + 1; j < n; j++){
				if(!vis.test(j)){
					S[j] ^= 1;
				}
			}
			if(tryCombination(S) == i){
				high = (ans = mid) - 1;
			}
			else{
				low = mid + 1;
			}
			for(int j = mid + 1; j < n; j++){
				if(!vis.test(j)){
					S[j] ^= 1;
				}
			}
		}
		D[ans] = i;
		S[ans] ^= 1;
		vis.set(ans);
	}
	answer(S, D);
}

Compilation message (stderr)

cave.cpp: In function 'void exploreCave(int)':
cave.cpp:22:30: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
   22 |   int low = 0, high = n - 1, ans;
      |                              ^~~

• Subtask 1: 12 / 12
• Subtask 2: 13 / 13
• Subtask 3: 21 / 21
• Subtask 4: 30 / 30
• Subtask 5: 24 / 24