#include <iostream>
#define U unsigned long long
U N, M, P, ind, a = 0;
U *matrixR, *matrixL, *matrixSquashed0, *matrixSquashed1;
void init() {
matrixR = new U[M];
matrixL = new U[M];
matrixSquashed0 = new U[M];
matrixSquashed1 = new U[M];
for (auto j = a; j < M; ++j)
{
matrixSquashed0[j] = 1;
matrixSquashed1[j] = 1;
matrixR[j] = 1;
matrixL[j] = 0;
}
while (--ind >= 1) matrixSquashed0[ind - 1] = matrixSquashed0[ind] + 1;
}
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(NULL);
std::cin >> N;
std::cin >> M;
ind = M;
std::cin >> P;
init();
for (U z = 0; z < N; ++z)
{
a = 0;
auto *matrixSquashedFrom = z % 2 ? matrixSquashed1 : matrixSquashed0;
auto *matrixSquashedTo = z % 2 ? matrixSquashed0 : matrixSquashed1;
auto *matrixTo = z % 2 ? matrixL : matrixR;
matrixTo[0] = matrixSquashedFrom[0];
auto sum = matrixTo[0];
for (auto ind = 1; ind < M; ++ind)
{
matrixTo[ind] = (matrixTo[ind - 1] + matrixSquashedFrom[ind]) % P;
sum = (sum + matrixTo[ind]) % P;
}
matrixSquashedTo[a] = sum % P;
for (auto ind = a + 1; ind < M; ++ind)
{
matrixSquashedTo[ind] = (matrixSquashedTo[ind - 1] + (P - (matrixTo[ind - 1] % P)) + a) % P;
auto symmetric_ind = M - ind;
a = (a + matrixSquashedFrom[symmetric_ind]) % P;
matrixSquashedTo[ind] = (matrixSquashedTo[ind] + (P - ((symmetric_ind * matrixSquashedFrom[symmetric_ind]) % P))) % P;
}
}
auto ans = N % 2 == 1 ? matrixR[M - 1] : matrixL[M - 1];
std::cout << ans << std::endl;
return 0;
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 | #include <iostream> #define U unsigned long long U N, M, P, ind, a = 0; U *matrixR, *matrixL, *matrixSquashed0, *matrixSquashed1; void init() { matrixR = new U[M]; matrixL = new U[M]; matrixSquashed0 = new U[M]; matrixSquashed1 = new U[M]; for (auto j = a; j < M; ++j) { matrixSquashed0[j] = 1; matrixSquashed1[j] = 1; matrixR[j] = 1; matrixL[j] = 0; } while (--ind >= 1) matrixSquashed0[ind - 1] = matrixSquashed0[ind] + 1; } int main() { std::ios_base::sync_with_stdio(false); std::cin.tie(NULL); std::cin >> N; std::cin >> M; ind = M; std::cin >> P; init(); for (U z = 0; z < N; ++z) { a = 0; auto *matrixSquashedFrom = z % 2 ? matrixSquashed1 : matrixSquashed0; auto *matrixSquashedTo = z % 2 ? matrixSquashed0 : matrixSquashed1; auto *matrixTo = z % 2 ? matrixL : matrixR; matrixTo[0] = matrixSquashedFrom[0]; auto sum = matrixTo[0]; for (auto ind = 1; ind < M; ++ind) { matrixTo[ind] = (matrixTo[ind - 1] + matrixSquashedFrom[ind]) % P; sum = (sum + matrixTo[ind]) % P; } matrixSquashedTo[a] = sum % P; for (auto ind = a + 1; ind < M; ++ind) { matrixSquashedTo[ind] = (matrixSquashedTo[ind - 1] + (P - (matrixTo[ind - 1] % P)) + a) % P; auto symmetric_ind = M - ind; a = (a + matrixSquashedFrom[symmetric_ind]) % P; matrixSquashedTo[ind] = (matrixSquashedTo[ind] + (P - ((symmetric_ind * matrixSquashedFrom[symmetric_ind]) % P))) % P; } } auto ans = N % 2 == 1 ? matrixR[M - 1] : matrixL[M - 1]; std::cout << ans << std::endl; return 0; } |
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