Submission #199754

#	Time	Username	Problem	Language	Result	Execution time	Memory
199754		Mercenary	Snake Escaping (JOI18_snake_escaping)	C++14	100 / 100	1924 ms	43416 KiB

snake_escaping

#include<bits/stdc++.h>

#define pb push_back
#define mp make_pair
#define taskname "A"

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int,int> ii;
const int maxn = (1 << 20);
string s;
int n , q;
int dp[2][maxn];
int res , f , nf , tmp;
int cnt[3] , a[maxn];

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if(fopen(taskname".INP","r")){
		freopen(taskname".INP", "r",stdin);
		freopen(taskname".OUT", "w",stdout);
    }
    cin >> n >> q >> s;
    for(int i = 0 ; i < (1 << n) ; ++i){
        dp[0][i] = dp[1][(1 << n) - 1 - i] = a[i] = s[i] - '0';
    }
    for(int i = 0 ; i < n ; ++i){
        for(int j = (1 << n) - 1 ; j >= 0 ; --j){
            if(j & (1 << i))dp[0][j ^ (1 << i)] += dp[0][j]  , dp[1][j ^ (1 << i)] += dp[1][j] ;
        }
    }
//    cout << dp[1][7];
    while(q--){
        cnt[0] = cnt[1] = cnt[2] = res = f = nf = 0;
        cin >> s;
        for(int i = 0 ; i < n ; ++i){
            if(s[i] == '0')s[i] = 0;
            else if(s[i] == '1')s[i] = 1;
            else s[i] = 2;
            cnt[s[i]] |= (1 << (n - i - 1));
        }
        tmp = min_element(cnt,cnt+3,[&](const int x , const int y){
            return __builtin_popcount(x)<__builtin_popcount(y);})-cnt;
        int *dp = ::dp[tmp];
        for(int i = cnt[tmp] ;; i = (i - 1) & cnt[tmp]){
            if(tmp < 2){
                if(__builtin_popcount(i) & 1)res -= dp[i | cnt[!tmp]];
                else res += dp[i | cnt[!tmp]];
            }else{
                res += a[i | cnt[1]];
            }
            if(i == 0)break;
        }
        cout << res << '\n';
    }
}

Compilation message (stderr)

snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:44:21: warning: array subscript has type 'char' [-Wchar-subscripts]
             cnt[s[i]] |= (1 << (n - i - 1));
                     ^
snake_escaping.cpp:24:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen(taskname".INP", "r",stdin);
   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
snake_escaping.cpp:25:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen(taskname".OUT", "w",stdout);
   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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