Submission #1222785

#	Time	Username	Problem	Language	Result	Execution time	Memory
1222785		huudai	Snake Escaping (JOI18_snake_escaping)	C++20	100 / 100	408 ms	20852 KiB

snake_escaping

#include <bits/stdc++.h>

using namespace std;

#define ll long long
#define fi first
#define se second
#define pii pair<int, int>
#define pll pair<ll,ll>
#define mp make_pair
#define pb push_back

#define BIT(x,i) (((x)>>(i))&1)
#define MASK(i) (1LL<<(i))  

template<typename T1, typename T2> bool minimize(T1 &a, T2 b)
    {if(a>b) a=b; else return 0; return 1;}
template<typename T1, typename T2> bool maximize(T1 &a, T2 b)
    {if(a<b) a=b; else return 0; return 1;}

#define file "task"

const int maxn = 1e5 + 5;
const int MOD  = 1e9 + 7;
const int oo   = 1e9;
const ll  OO   = 1e18;

int n;
int q;
int a[MASK(20)];
int sosSub[MASK(20)];
int sosSuper[MASK(20)];

void input(){
    cin >> n >> q;
    string st; cin >> st;
    for(int i = 0; i < MASK(n); i++) a[i] = st[i] - '0';
}

void proc(){
    for(int i = 0; i < MASK(n); i++){
        sosSub[i] = sosSuper[i] = a[i]; 
    }

    for(int i = 1; i <= n; i++){
        for(int mask = 0; mask < MASK(n); mask++){
            if(BIT(mask, i - 1))
                sosSub[mask] += sosSub[mask ^ MASK(i - 1)];
            else 
                sosSuper[mask] += sosSuper[mask ^ MASK(i - 1)];
        }
    }

    for(int i = 1; i <= q; i++){
        string st; cin >> st;
        reverse(st.begin(), st.end());

        int maskZero, maskOne, maskQues;
        maskZero = maskOne = maskQues = 0;
        for(int i = 0; i < n; i++){
            if(st[i] == '0') maskZero |= MASK(i);
            if(st[i] == '1') maskOne  |= MASK(i);
            if(st[i] == '?') maskQues |= MASK(i);
        }

        int ans = 0;
        if(__builtin_popcount(maskQues) <= 6){
            for(int mask = maskQues; mask >= 0; mask = (mask - 1) & maskQues){
                ans += a[mask | maskOne];
                if(mask == 0) break;
            }
        } else if(__builtin_popcount(maskOne) <= 6){
            //dem phan bu
            int sum = 0;
            for(int mask = (maskOne - 1) & maskOne; maskOne != 0 && mask >= 0; mask = (mask - 1) & maskOne){
                if(__builtin_popcount(maskOne ^ mask) % 2)
                    sum += sosSub[mask | maskQues];
                else 
                    sum -= sosSub[mask | maskQues];
                if(mask == 0) break;
            }
            ans = sosSub[maskOne | maskQues] - sum;
        } else{
            // dem phan bu
            int sum = 0;
            for(int mask = maskZero; mask > 0; mask = (mask - 1) & maskZero){
                if(__builtin_popcount(mask) % 2)
                    sum += sosSuper[mask | maskOne];
                else    
                    sum -= sosSuper[mask | maskOne];
            }
            ans = sosSuper[maskOne] - sum;
        }

        cout << ans << '\n';
    }
}

signed main(){
    cin.tie(nullptr)->sync_with_stdio(0); cout.tie(nullptr);    
    if(fopen(file".inp", "r")){
        freopen(file".inp", "r", stdin);
        freopen(file".out", "w", stdout);
    }
    
    input();
    proc();
    return 0;
}

Compilation message (stderr)

snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:102:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |         freopen(file".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
snake_escaping.cpp:103:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  103 |         freopen(file".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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