Submission #104678

#	Time	Username	Problem	Language	Result	Execution time	Memory
104678		Erkhemkhuu	Cave (IOI13_cave)	C++17	100 / 100	534 ms	560 KiB

cave

#include <bits/stdc++.h>
#include "cave.h"
using namespace std;
#define n 5005
bool vis[n + 5];
int ind[n + 5], switches[n + 5];
void run(int l, int r, bool flag) {
	int i;
	for(i = l; i <= r; i++)
		if(!vis[i]) switches[i] = flag;
	return;
}
void exploreCave(int N) {
	memset(vis, false, sizeof(vis));
	memset(ind, 0, sizeof(ind));
	int i, l, r, mid;
	bool flag;
	for(i = 0; i < N; i++) {
		run(0, N - 1, false);
		flag = tryCombination(switches) == i;
		l = 0; r = N ;
		while(l != r) {
			int mid = (l + r) / 2;
			run(l, mid, flag);
			run(mid + 1, r, flag ^ 1);
			if(tryCombination(switches) == i) l = mid + 1;
			else r = mid;
		}
		vis[l] = true;
		switches[l] = flag;
		ind[l] = i;
	}
	answer(switches, ind);
    return;
}

Compilation message (stderr)

cave.cpp: In function 'void exploreCave(int)':
cave.cpp:16:15: warning: unused variable 'mid' [-Wunused-variable]
  int i, l, r, mid;
               ^~~

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