Submission #66808

#	Time	Username	Problem	Language	Result	Execution time	Memory
66808		hamzqq9	Snake Escaping (JOI18_snake_escaping)	C++14	12 / 100	1937 ms	66560 KiB

snake_escaping

#include<bits/stdc++.h>
#define st first
#define nd second
#define pb push_back
#define ppb pop_back
#define umax(x,y) x=max(x,y)
#define umin(x,y) x=min(x,y)
#define ll long long
#define ii pair<int,int>
#define iii pair<int,ii>
#define sz(x) ((int) x.size())
#define orta ((bas+son)>>1)
#define all(x) x.begin(),x.end()
#define dbgs(x) cerr<<(#x)<<" --> "<<(x)<<" "
#define dbg(x) cerr<<(#x)<<" --> "<<(x)<<endl;getchar()
#define pw(x) (1<<(x))
#define inf 100000000000000
#define MOD 1000000007
#define N 100005
#define MAX 10000006
#define L 12
#define R 8
#define LOG 22
using namespace std;

unsigned short int ans[pw(L)][6566];
char val[pw(20)+3];
int po3[12];
int l,q,n;
int res,value;
char s[pw(20)+3];
int sz;
pair<char,short int> stck[pw(L)+5];

int get_pos_of_2(int value) {

	int cur=0;

	while(value) {

		if(value%3==2) return cur;

		value/=3;

		cur++;

	}

	return -1;

}

int get_val(int bas,int son) {

	int cur=0;

	for(int i=bas;i<=son;i++) {

		cur+=po3[son-i]*(s[i]=='?'?2:(s[i]-'0'));

	}

	return cur;

}

int get_2_rep(int val) {

	int res=0;

	int curpw=1;

	while(val) {

		res+=curpw*(val%3);

		curpw*=2;

		val/=3;

	}

	return res;

}

void back_track(char bit,short int val) {

	stck[sz++]={bit,val};

	while(sz) {

		sz--;

		char bit=stck[sz].st;
		short int val=stck[sz].nd;

		if(bit==-1) {

			res+=ans[val][value];

			continue ;

		}

		if(s[bit]!='?') {
		
			stck[sz++]={bit-1,val+pw(L-1-bit)*(s[bit]=='1')};
		}
		else {

			stck[sz++]={bit-1,val+pw(L-1-bit)};
			stck[sz++]={bit-1,val};

		}

	}

} 

void pre_calc() {

	for(int i=0;i<po3[R];i++) {

		char pos=get_pos_of_2(i);

		short int temp=-1;

		if(pos==-1) temp=get_2_rep(i);

		for(int j=0;j<pw(L);j++) {

			if(pos==-1) {

				ans[j][i]=val[temp+pw(R)*j];

			}
			else {

				ans[j][i]=ans[j][i-po3[pos]]+ans[j][i-po3[pos]*2];

			}

		}

	}

}

int main() {

//	freopen("input.txt","r",stdin);

	scanf("%d %d",&l,&q);

	po3[0]=1;

	for(int i=1;i<=10;i++) po3[i]=po3[i-1]*3;

	n=pw(l);

	scanf("%s",s);

	for(int i=0;i<n;i++) {

		val[i]=s[i]-'0';

	}

	pre_calc();

	while(q--) {

		scanf("%s",s+20-l);

		for(int i=0;i<20-l;i++) s[i]='0';

		res=0;

		value=get_val(L,19);

		back_track(L-1,0);

		printf("%d\n",res);

	}

}

Compilation message (stderr)

snake_escaping.cpp: In function 'void back_track(char, short int)':
snake_escaping.cpp:106:11: warning: array subscript has type 'char' [-Wchar-subscripts]
   if(s[bit]!='?') {
           ^
snake_escaping.cpp:108:44: warning: array subscript has type 'char' [-Wchar-subscripts]
    stck[sz++]={bit-1,val+pw(L-1-bit)*(s[bit]=='1')};
                                            ^
snake_escaping.cpp: In function 'void pre_calc()':
snake_escaping.cpp:140:31: warning: array subscript has type 'char' [-Wchar-subscripts]
     ans[j][i]=ans[j][i-po3[pos]]+ans[j][i-po3[pos]*2];
                               ^
snake_escaping.cpp:140:50: warning: array subscript has type 'char' [-Wchar-subscripts]
     ans[j][i]=ans[j][i-po3[pos]]+ans[j][i-po3[pos]*2];
                                                  ^
snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:154:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&l,&q);
  ~~~~~^~~~~~~~~~~~~~~
snake_escaping.cpp:162:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s",s);
  ~~~~~^~~~~~~~
snake_escaping.cpp:174:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%s",s+20-l);
   ~~~~~^~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 0 / 10
• Subtask 4: 0 / 53
• Subtask 5: 0 / 25