Submission #43301

#	Time	Username	Problem	Language	Result	Execution time	Memory
43301		funcsr	Snake Escaping (JOI18_snake_escaping)	C++14	100 / 100	1591 ms	65536 KiB

snake_escaping

#include <cstdio>
#include <algorithm>
#include <string>
#include <cstring>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cmath>
#include <iomanip>
#include <cassert>
#include <bitset>
using namespace std;

typedef pair<int, int> P;
#define rep(i, n) for (int i=0; i<(n); i++)
#define all(c) (c).begin(), (c).end()
#define uniq(c) c.erase(unique(all(c)), (c).end())
#define index(xs, x) (int)(lower_bound(all(xs), x) - xs.begin())
#define _1 first
#define _2 second
#define pb push_back
#define INF 1145141919
#define MOD 1000000007

int L, Q;
char IN[(1<<20)+1];
int A[1<<20], B[1<<20], C[1<<20];
char qs[21];
int sub[20];

signed main() {
  scanf("%d %d", &L, &Q);
  scanf("%s", IN);
  rep(i, 1<<L) A[i] = (int)(IN[i]-'0');
  rep(i, 1<<L) B[i] = A[i], C[((1<<L)-1)^i] = A[i];
  rep(add, L) rep(S, 1<<L) if (((S>>add)&1)==0) B[S|(1<<add)] += B[S];
  rep(add, L) rep(S, 1<<L) if (((S>>add)&1)==0) C[S|(1<<add)] += C[S];

  rep(q, Q) {
    scanf("%s", qs);
    rep(i, L/2) swap(qs[i], qs[L-1-i]);
    int zero = 0, one = 0, any = 0;
    rep(i, L) {
      if      (qs[i] == '0') zero++;
      else if (qs[i] == '1') one++;
      else                   any++;
    }
    int s = 0;
    int minsz = min(zero, min(one, any));

    if (any == minsz) {
      int sub = 0, mask = 0;
      rep(i, L) {
        if (qs[i] == '?') sub |= 1<<i;
        else if (qs[i] == '1') mask |= 1<<i;
      }
      s += A[mask];
      for (int id=sub; id>0; id=(id-1)&sub) s += A[id|mask];
    }
    else if (one == minsz) {
      int sz = 0, sub = 0, mask = 0;
      rep(i, L) {
        if (qs[i] == '1') sub |= 1<<i, sz ^= 1;
        else if (qs[i] == '?') mask |= 1<<i;
      }
      s += B[mask];
      for (int id=sub; id>0; id=(id-1)&sub) {
        if ((__builtin_popcount(id))&1) s -= B[id|mask];
        else s += B[id|mask];
      }
      if (sz) s = -s;
    }
    else {
      int sz = 0, sub = 0, mask = 0;
      rep(i, L) {
        if (qs[i] == '0') sub |= 1<<i, sz ^= 1;
        else if (qs[i] == '?') mask |= 1<<i;
      }
      s += C[mask];

      for (int id=sub; id>0; id=(id-1)&sub) {
        if ((__builtin_popcount(id))&1) s -= C[id|mask];
        else s += C[id|mask];
      }
      if (sz) s = -s;
    }
    printf("%d\n", s);
  }
  return 0;
}

Compilation message (stderr)

snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:33:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &L, &Q);
                         ^
snake_escaping.cpp:34:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%s", IN);
                  ^
snake_escaping.cpp:41:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s", qs);
                    ^

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