Submission #331804

#	Time	Username	Problem	Language	Result	Execution time	Memory
331804		daniel920712	Snake Escaping (JOI18_snake_escaping)	C++14	0 / 100	1 ms	384 KiB

snake_escaping

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <vector>
#include <string.h>
#include <map>
#include <utility>
#include <algorithm>
#include <stack>
#include <queue>
using namespace std;
char all[1148576];
char tt[25];
int con1[2][1100005];
int con2[2][1100005];
int ans=0;
int N;
queue < pair < pair < int , int > , int > > BFS;
vector < int > xxx;
int main()
{
    //freopen("05-05.txt","rt",stdin);
    //freopen("tt.txt","w+t",stdout);
    int M,i,j,ok,a,b,c,x,y,z,con=0,xx;
    scanf("%d %d",&N,&M);
    scanf("%s",all);
    for(i=0;i<(1<<N);i++) con2[0][i]=con1[0][i]=all[i]-'0';
    for(i=0;i<N;i++)
    {
        for(j=0;j<(1<<N);j++)
        {
            con1[1-i%2][j]=con1[i%2][j];
            con2[1-i%2][j]=con2[i%2][j];
            if(j&(1<<i)) con1[1-i%2][j]+=con1[i%2][j-(1<<i)];
            else con2[1-i%2][j]+=con2[i%2][j+(1<<i)];
        }
    }



    while(M--)
    {
        scanf("%s",tt);
        ans=0;
        a=0;
        b=0;
        c=0;
        for(i=0;i<N;i++)
        {
            if(tt[i]=='?') a++;
            else if(tt[i]=='1') b++;
            else c++;
        }

        xxx.clear();
        con=0;
        if(b<=a&&b<=c)
        {
            for(i=0;i<N;i++)
            {
                if(tt[i]=='1') xxx.push_back(i);
                else if(tt[i]=='?') con+=(1<<(N-i-1));
            }


            BFS.push(make_pair(make_pair(0,con),0));
            while(!BFS.empty())
            {
                x=BFS.front().first.first;
                y=BFS.front().first.second;
                z=BFS.front().second;
                BFS.pop();
                if(x==b)
                {
                    if(z==0) ans+=con1[N%2][y];
                    else ans-=con1[N%2][y];
                    continue;
                }
                xx=xxx[x];

                BFS.push(make_pair(make_pair(x+1,y+(1<<(N-xx-1))),z));
                BFS.push(make_pair(make_pair(x+1,y),z^1));


            }
        }
        else if(a<=b&&a<=c)
        {
            for(i=0;i<N;i++)
            {
                if(tt[i]=='?') xxx.push_back(i);
                else con+=(1<<(N-i-1));
            }
            BFS.push(make_pair(make_pair(0,y),0));
            while(!BFS.empty())
            {
                x=BFS.front().first.first;
                y=BFS.front().first.second;
                z=BFS.front().second;
                BFS.pop();
                if(x==a)
                {
                    ans+=(all[y]-'0');
                    continue;
                }

                xx=xxx[x];
                BFS.push(make_pair(make_pair(x+1,y+(1<<(N-xx-1))),z));
                BFS.push(make_pair(make_pair(x+1,y),z));

            }
        }
        else if(c<=b&&c<=a)
        {
            for(i=0;i<N;i++)
            {
                if(tt[i]=='0') xxx.push_back(i);
                else if(tt[i]=='1') con+=(1<<(N-i-1));
            }


            BFS.push(make_pair(make_pair(0,con),0));
            while(!BFS.empty())
            {
                x=BFS.front().first.first;
                y=BFS.front().first.second;
                z=BFS.front().second;

                BFS.pop();
                if(x==c)
                {
                    if(z==0) ans+=con2[N%2][y];
                    else ans-=con2[N%2][y];
                    continue;
                }
                xx=tt[x];
                BFS.push(make_pair(make_pair(x+1,y+(1<<(N-xx-1))),z^1));
                BFS.push(make_pair(make_pair(x+1,y),z));


            }
        }
        printf("%d\n",ans);
    }

	return 0;
}

Compilation message (stderr)

snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:24:15: warning: unused variable 'ok' [-Wunused-variable]
   24 |     int M,i,j,ok,a,b,c,x,y,z,con=0,xx;
      |               ^~
snake_escaping.cpp:25:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   25 |     scanf("%d %d",&N,&M);
      |     ~~~~~^~~~~~~~~~~~~~~
snake_escaping.cpp:26:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   26 |     scanf("%s",all);
      |     ~~~~~^~~~~~~~~~
snake_escaping.cpp:43:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   43 |         scanf("%s",tt);
      |         ~~~~~^~~~~~~~~
snake_escaping.cpp:94:48: warning: 'y' may be used uninitialized in this function [-Wmaybe-uninitialized]
   94 |             BFS.push(make_pair(make_pair(0,y),0));
      |                                                ^

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