Submission #16333

#	Time	Username	Problem	Language	Result	Execution time	Memory
16333		comet	Cave (IOI13_cave)	C++98	100 / 100	393 ms	608 KiB

cave

#include <cstring>
#include "cave.h"
int a[5000],b[5000],p,n;
bool flip(int L,int R){
	bool ret=0;
	for(int i=L;i<=R;i++){
		if(b[i]<0)a[i]=!a[i],ret=1;
	}
	return ret;
}
void finish(){
	for(int i=0;i<n;i++){
		if(b[i]<0){
			a[i]=!a[i];
			b[i]=tryCombination(a);
			a[i]=!a[i];
		}
	}
	answer(a,b);
}
void f(int L,int R,int v){
	if(L==R){
		b[L]=v;
		if(p==v)a[L]=!a[L];
		return;
	}
	int mid=(L+R)/2;
	if(!flip(L,mid)){
		f(mid+1,R,v);
		return;
	}
	int t=tryCombination(a);
	if(t<0)finish();
	flip(L,mid);
	if((p!=v&&t!=v)||p==t)f(mid+1,R,v);
	else f(L,mid,v);
}
void exploreCave(int N){
	n=N;
	memset(b,-1,sizeof(b));
	for(int i=0;i<N;i++){
		p=tryCombination(a);
		if(p<0)finish();
		f(0,N-1,i);
	}
	answer(a,b);
}

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