#include #include #include #include using namespace std; long long INF = 1000000000000LL, BB = 1000000LL, T = 1LL; vectorkakezan(vectorA, vectorB) { vectorC(A.size() + B.size(), 0); for (int i = 0; i < A.size(); i++) { for (int j = 0; j < B.size(); j++) { C[i + j] += A[i] * B[j]; if (C[i + j] >= INF) { C[i + j + 1] += BB; C[i + j] -= INF; } } } for (int i = 0; i < C.size() - 1; i++) { C[i + 1] += C[i] / BB; C[i] %= BB; } while (C[C.size() - 1] == 0 && C.size() >= 2) C.pop_back(); return C; } vectortashizan(vectorA, vectorB) { vectorC(max(A.size(), B.size()) + 1); for (int i = 0; i < A.size(); i++) C[i] += A[i]; for (int i = 0; i < B.size(); i++) C[i] += B[i]; for (int i = 0; i < C.size() - 1; i++) { C[i + 1] += C[i] / BB; C[i] %= BB; } while (C[C.size() - 1] == 0 && C.size() >= 2) C.pop_back(); return C; } int bit[100009]; void add(int pos, int x) { while (pos <= 100008) { bit[pos] += x; pos += (pos&-pos); } } int sum(int pos) { int s = 0; while (pos >= 1) { s += bit[pos]; pos -= (pos&-pos); } return s; } long long N, P[100009], S[100009]; vectorfactorial(long long L, long long R) { if (R - L == 1) return vector{L}; return kakezan(factorial(L, (L + R) / 2), factorial((L + R) / 2, R)); } vectorsolve(long long L, long long R) { if (R - L == 1) return vector{S[L]}; return tashizan(solve(L, (L + R) / 2), kakezan(solve((L + R) / 2, R), factorial(L, (L + R) / 2))); } int main() { cin >> N; for (int i = 1; i <= N; i++) cin >> P[i]; for (int i = N; i >= 1; i--) { S[i] = sum(P[i]); add(P[i], 1); } reverse(S + 1, S + N + 1); S[1]++; vectorD = solve(1, N + 1); for (int i = D.size() - 1; i >= 0; i--) { string S = to_string(D[i]); if (i < (int)D.size() - 1) { while (S.size() < T) S = "0" + S; } cout << S; } cout << endl; return 0; }