Submission #1095961

#	Time	Username	Problem	Language	Result	Execution time	Memory
1095961		phamducluong	Snake Escaping (JOI18_snake_escaping)	C++14	100 / 100	493 ms	43272 KiB

snake_escaping

#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>

//using namespace __gnu_pbds;
using namespace std;
//typedef tree<int,null_type,less_equal<int>,rb_tree_tag, tree_order_statistics_node_update> ordered_set;
#define Sakura_chan    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define mem(a,x)       memset(a,x,sizeof(a))
#define fast(s)        s.reserve(2000); s.max_load_factor(0.5);
#define ll             long long
#define F              first
#define S              second
#define pb             push_back
#define ins            insert
#define pii            pair <long long, long long>
#define vpii           vector <pii>
#define sz             size()
#define all(p)         p.begin(), p.end()
#define For(i,a,b)     for(int i=a; i<=b; ++i)
#define rFor(i,a,b)    for(int i=a; i>=b; --i)
#define Auto(it,a)     for(auto it: a)
const int mod=1e9+7;
const int N=1e6+5, M=20;
int n, q, f[1<<M], g[1<<M], cnt[1<<M];
string s, t;
void file()
{
    #define task "snakes"
    if(fopen(task".inp","r"))
    {
        freopen(task".inp","r",stdin);
        freopen(task".out","w",stdout);
    }
    Sakura_chan;
}
void Solve()
{
    cin>>n>>q>>s;
    for(int i=0; i<(1<<n); ++i) f[i]=g[i]=(s[i]-'0');
    for(int i=0; i<n; ++i) for(int mask=0; mask<(1<<n); ++mask) if(mask&(1<<i)) {f[mask]+=f[mask^(1<<i)]; g[mask^(1<<i)]+=g[mask];}
    for(int i=0; i<(1<<n); ++i) cnt[i]=__builtin_popcount(i);
    while(q--)
    {
        cin>>t;
        reverse(all(t));
        int a=0, b=0, c=0;
        ll res=0;
        for(int i=0; i<n; ++i)
        {
            if(t[i]=='?') a|=(1<<i);
            else if(t[i]=='0') b|=(1<<i);
            else c|=(1<<i);
        }
        if(cnt[a]<=n/3)
        {
            for(int mask=a;;mask=(mask-1)&a)
            {
                res+=s[c|mask]-'0';
                if(mask==0) break;
            }
        }
        else if(cnt[b]<=n/3)
        {
            for(int mask=b;;mask=(mask-1)&b)
            {
                if(cnt[mask]&1) res-=g[c|mask];
                else res+=g[c|mask];
                if(mask==0) break;
            }
        }
        else
        {
            for(int mask=c;;mask=(mask-1)&c)
            {
                if((cnt[c]-cnt[mask])&1) res-=f[a|mask];
                else res+=f[a|mask];
                if(mask==0) break;
            }
        }
        cout<<res<<"\n";
    }
}

main()
{
    file();
    Solve();
    return 0;
}

Compilation message (stderr)

snake_escaping.cpp:84:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   84 | main()
      | ^~~~
snake_escaping.cpp: In function 'void file()':
snake_escaping.cpp:31:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |         freopen(task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
snake_escaping.cpp:32:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |         freopen(task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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