oj.uz

Submission #153078

# Submission time Handle Problem Language Result Execution time Memory
153078 2019-09-12T09:06:21 Z admin Round words (IZhO13_rowords) C++14
100 / 100
 186 ms 504 KB 
#include <bits/stdc++.h>

#define get(arr, x) (((arr[x >> 6] >> (x & 63)) & 1) == 1)
#define set(arr, x) (arr[x >> 6] |= 1llu << (x & 63))
using ulint = unsigned long long;

int lcs(std::string A, std::string B) {
  int N = A.size(), M = B.size();
  int sz = (M >> 6) + 1;

  std::vector<ulint> S[256];
  for(int c = 0; c < 256; c++) S[c].resize(sz);
  for(int j = 0; j < M; j++) set(S[B[j]], j);
  
  std::vector<ulint> row(sz);
  for(int j = 0; j < M; j++) if(A[0] == B[j]) { set(row, j); break; }

  for(int i = 1; i < N; i++) {
    ulint shl_carry = 1;
    ulint minus_carry = 0;
    
    for(int k = 0; k < sz; k++) {
      // Compute k-th block of x == S[A[i]] OR M[i-1]
      ulint x_k = S[A[i]][k] | row[k];

      // Compute k-th block of "(M[i-1] << 1) | 1"
      ulint term_1 = (row[k] << 1) | shl_carry;
      shl_carry = row[k] >> 63;

      // Compute k-th block of "x - ((M[i-1] << 1) | 1)"
      auto sub_carry = [](ulint &x, ulint y){
        ulint tmp = x;
        return (x = tmp - y) > tmp;
      };
      ulint term_2 = x_k;
      minus_carry = sub_carry(term_2, minus_carry);
      minus_carry += sub_carry(term_2, term_1);
      
      row[k] = x_k & (x_k ^ term_2);
    }

    row[M >> 6] &= (1llu << (M & 63)) - 1;
  }

  int ret = 0;
  for(int j = 0; j < M; j++) if(get(row, j)) ret += 1;
  return ret;
}

int main() {
  std::string a, b;
  std::cin >> a >> b;

  int ans = 0;
  
  for(int rep = 0; rep < 2; rep++) {
    for(int i = 0; i < int(b.size()); i++) {
      ans = std::max(ans, lcs(a, b));
      std::rotate(b.begin(), b.begin() + 1, b.end());
    }
    std::reverse(b.begin(), b.end());
  }
  std::cout << ans << std::endl;
  return 0;
}

Compilation message

rowords.cpp: In function 'int lcs(std::__cxx11::string, std::__cxx11::string)':
rowords.cpp:13:40: warning: array subscript has type 'char' [-Wchar-subscripts]
   for(int j = 0; j < M; j++) set(S[B[j]], j);
                                        ^
rowords.cpp:4:22: note: in definition of macro 'set'
 #define set(arr, x) (arr[x >> 6] |= 1llu << (x & 63))
                      ^~~
rowords.cpp:24:25: warning: array subscript has type 'char' [-Wchar-subscripts]
       ulint x_k = S[A[i]][k] | row[k];
                         ^

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 256 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 3 ms 376 KB Output is correct
5 Correct 3 ms 256 KB Output is correct
6 Correct 11 ms 380 KB Output is correct
7 Correct 142 ms 504 KB Output is correct
8 Correct 137 ms 376 KB Output is correct
9 Correct 137 ms 504 KB Output is correct
10 Correct 137 ms 376 KB Output is correct
11 Correct 145 ms 376 KB Output is correct
12 Correct 171 ms 376 KB Output is correct
13 Correct 168 ms 376 KB Output is correct
14 Correct 146 ms 376 KB Output is correct
15 Correct 186 ms 376 KB Output is correct
16 Correct 143 ms 400 KB Output is correct
17 Correct 67 ms 376 KB Output is correct
18 Correct 141 ms 376 KB Output is correct
19 Correct 134 ms 404 KB Output is correct
20 Correct 131 ms 292 KB Output is correct
21 Correct 13 ms 376 KB Output is correct
22 Correct 24 ms 256 KB Output is correct
23 Correct 39 ms 376 KB Output is correct
24 Correct 39 ms 376 KB Output is correct
25 Correct 62 ms 388 KB Output is correct