Submission #81072

#	Time	Username	Problem	Language	Result	Execution time	Memory
81072		arman_ferdous	Cave (IOI13_cave)	C++17	100 / 100	372 ms	548 KiB

cave

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

void exploreCave(int N) {
    int S[N], D[N];
    memset(S,0,sizeof S);
    memset(D,-1,sizeof D);

    for(int i = 0; i < N; i++) {
    	int bad = tryCombination(S);
    	int stat = (bad == i);
    	int lo = 0, hi = N-1, idx;
    	while(lo <= hi) {
    		int mid = (lo + hi) >> 1;
    		
    		for(int i = lo; i <= mid; i++) if(D[i] == -1) S[i] ^= 1;
    		int blok = tryCombination(S);
    		for(int i = lo; i <= mid; i++) if(D[i] == -1) S[i] ^= 1;

    		if(stat == 0) {
    			if(blok == i) idx = mid, hi = mid-1;
    			else lo = mid+1;
    		} else {
    			if(blok > i || blok == -1) idx = mid, hi = mid-1;
    			else lo = mid+1;
    		}
    	}
    	D[idx] = i;
    	S[idx] = stat;
    } answer(S,D);
}

Compilation message (stderr)

cave.cpp: In function 'void exploreCave(int)':
cave.cpp:29:13: warning: 'idx' may be used uninitialized in this function [-Wmaybe-uninitialized]
      D[idx] = i;
      ~~~~~~~^~~

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