Submission #1023355

#	Time	Username	Problem	Language	Result	Execution time	Memory
1023355		snpmrnhlol	Snake Escaping (JOI18_snake_escaping)	C++17	100 / 100	674 ms	42180 KiB

snake_escaping

#include<bits/stdc++.h>
using namespace std;
const int N = 20;
int cost[1<<N],cost0[1<<N],cost1[1<<N];
vector <int> pos;
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n,q;
    cin>>n>>q;
    for(int i = 0;i < (1<<n);i++){
        char ch;
        cin>>ch;
        ch-='0';
        cost[i]+=ch;
        cost0[i]+=ch;
        cost1[i]+=ch;
    }
    for(int i = 0;i < n;i++){
        for(int j = 0;j < (1<<i);j++){
            for(int k = 0;k < (1<<n);k+=(1<<(i + 1))){
                cost0[(1<<i) + j + k]+=cost0[j + k];
                ///0 - 0
                ///1 - 0 and 1
            }
        }
    }
    for(int i = 0;i < n;i++){
        for(int j = 0;j < (1<<i);j++){
            for(int k = 0;k < (1<<n);k+=(1<<(i + 1))){
                cost1[j + k]+=cost1[j + k + (1<<i)];
                ///0 - 0 and 1
                ///1 - 1
            }
        }
    }
    for(int i = 0;i < q;i++){
        int cnt[3];
        cnt[0] = cnt[1] = cnt[2] = 0;
        string x;
        cin>>x;
        for(int j = 0;j < x.size();j++){
            if(x[j] == '0'){
                cnt[0]++;
            }else if(x[j] == '1'){
                cnt[1]++;
            }else{
                cnt[2]++;
            }
        }
        pos.clear();
        if(cnt[0] <= min(cnt[1],cnt[2])){
            ///0 count low
            ///use cost1
            for(int k = 0;k < n;k++){
                if(x[k] == '0'){
                    pos.push_back(n - k - 1);
                }
            }
            int nr = 0;
            for(int k = 0;k < n;k++){
                if(x[k] == '1'){
                    nr = nr*2 + 1;
                }else{
                    nr = nr*2;
                }
            }
            int ans = 0;
            for(int k = 0;k < (1<<pos.size());k++){
                if(k%2 == 0)ans+=cost1[nr];
                else ans-=cost1[nr];
                if(k != (1<<pos.size()) - 1)nr^=(1<<pos[__builtin_ctz(k + 1)]);
            }
            cout<<ans<<'\n';
        }else if(cnt[1] <= min(cnt[2],cnt[0])){
            ///1 count low
            ///use cost0
            for(int k = 0;k < n;k++){
                if(x[k] == '1'){
                    pos.push_back(n - k - 1);
                }
            }
            int nr = 0;
            for(int k = 0;k < n;k++){
                if(x[k] == '0'){
                    nr = nr*2;
                }else{
                    nr = nr*2 + 1;
                }
            }
            int ans = 0;
            for(int k = 0;k < (1<<pos.size());k++){
                if(k%2 == 0)ans+=cost0[nr];
                else ans-=cost0[nr];
                if(k != (1<<pos.size()) - 1)nr^=(1<<pos[__builtin_ctz(k + 1)]);
            }
            cout<<ans<<'\n';
        }else{
            ///? count low
            ///use cost
            for(int k = 0;k < n;k++){
                if(x[k] == '?'){
                    pos.push_back(n - k - 1);
                }
            }
            int nr = 0;
            for(int k = 0;k < n;k++){
                if(x[k] == '1'){
                    nr = nr*2 + 1;
                }else{
                    nr = nr*2;
                }
            }
            int ans = 0;
            for(int k = 0;k < (1<<pos.size());k++){
                ans+=cost[nr];
                //cout<<nr<<' '<<(1<<__builtin_ctz(k + 1))<<'\n';
                if(k != (1<<pos.size()) - 1)nr^=(1<<pos[__builtin_ctz(k + 1)]);
            }
            cout<<ans<<'\n';
        }
    }
    return 0;
}

Compilation message (stderr)

snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:42:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |         for(int j = 0;j < x.size();j++){
      |                       ~~^~~~~~~~~~

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