Submission #1691052
Source Code Expand
#include <cstdio> #include <vector> #include <algorithm> using namespace std; #define iter(i, n) for (int i = 1; i <= n; ++i) #define NR 101000 const int mod = 1e9 + 7; int n, a[NR], in[NR], in_x[NR], cnt[NR], f[NR], cc[NR], sz; bool vis[NR], ring[NR]; vector<int> R[NR]; int main() { scanf("%d", &n); iter(i, n) { scanf("%d", &a[i]); ++in[a[i]]; in_x[a[i]] = i; } iter(i, n) if (in[i] > 2) { puts("0"); return 0; } int ans = 1; iter(i, n) if (!vis[i]) { int x = i; bool is_ring = true; for (; !vis[x]; x = a[x]) { vis[x] = true; } if (!ring[x]) { ++sz; for (; !ring[x]; x = a[x]) { if (in[x] != 1) is_ring = false; ring[x] = true; R[sz].push_back(x); } } if (x != i) { bool is_chain = true; x = i; while (in[x] == 1) x = in_x[x]; if (in[x] != 0) { puts("0"); return 0; } int len = 1; for (vis[x] = true, x = a[x]; !ring[x]; x = a[x]) { ++len; vis[x] = true; if (in[x] != 1) { puts("0"); return 0; } } cc[x] = len; } else { if (is_ring) ++cnt[R[sz].size()]; } } iter(i, sz) { reverse(R[i].begin(), R[i].end()); int rem = 0; for (int x : R[i]) { if (cc[x] != 0) { if (rem > 1) { puts("0"); return 0; } else rem = cc[x]; } else if (rem != 0) { --rem; if (rem == 0) ans = ans * 2 % mod; } } if (rem != 0) { for (int x : R[i]) { if (cc[x] != 0) { if (rem > 1) { puts("0"); return 0; } else break; } else { --rem; if (rem == 0) { ans = ans * 2 % mod; break; } } } } } iter(k, n) { f[0] = 1; iter(i, cnt[k]) { f[i] = f[i - 1] * ((k % 2 && k != 1) ? 2 : 1) % mod; if (i > 1) f[i] = (f[i] + 1ll * (i - 1) * f[i - 2] % mod * k) % mod; } ans = 1ll * ans * f[cnt[k]] % mod; } printf("%d\n", ans); return 0; }
Submission Info
Submission Time | |
---|---|
Task | E - Next or Nextnext |
User | Ketsui |
Language | C++14 (GCC 5.4.1) |
Score | 1400 |
Code Size | 1905 Byte |
Status | AC |
Exec Time | 21 ms |
Memory | 8320 KB |
Compile Error
./Main.cpp: In function ‘int main()’: ./Main.cpp:16:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ ./Main.cpp:18:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i]); ^
Judge Result
Set Name | Sample | All | ||||
---|---|---|---|---|---|---|
Score / Max Score | 0 / 0 | 1400 / 1400 | ||||
Status |
|
|
Set Name | Test Cases |
---|---|
Sample | 0_00.txt, 0_01.txt, 0_02.txt, 0_03.txt, 0_04.txt |
All | 0_00.txt, 0_01.txt, 0_02.txt, 0_03.txt, 0_04.txt, 1_00.txt, 1_01.txt, 1_02.txt, 1_03.txt, 1_04.txt, 1_05.txt, 1_06.txt, 1_07.txt, 1_08.txt, 1_09.txt, 1_10.txt, 1_11.txt, 1_12.txt, 1_13.txt, 1_14.txt, 1_15.txt, 1_16.txt, 1_17.txt, 1_18.txt, 1_19.txt, 1_20.txt, 1_21.txt, 1_22.txt, 1_23.txt, 1_24.txt, 1_25.txt, 1_26.txt, 1_27.txt, 1_28.txt, 1_29.txt, 1_30.txt, 1_31.txt, 1_32.txt, 1_33.txt, 1_34.txt, 1_35.txt, 1_36.txt, 1_37.txt, 1_38.txt, 1_39.txt, 1_40.txt, 1_41.txt, 1_42.txt, 1_43.txt, 1_44.txt, 1_45.txt, 1_46.txt, 1_47.txt, 1_48.txt, 1_49.txt, 1_50.txt, 1_51.txt, 1_52.txt, 1_53.txt |
Case Name | Status | Exec Time | Memory |
---|---|---|---|
0_00.txt | AC | 3 ms | 4352 KB |
0_01.txt | AC | 3 ms | 4352 KB |
0_02.txt | AC | 3 ms | 4352 KB |
0_03.txt | AC | 3 ms | 4352 KB |
0_04.txt | AC | 3 ms | 4352 KB |
1_00.txt | AC | 3 ms | 4352 KB |
1_01.txt | AC | 21 ms | 8320 KB |
1_02.txt | AC | 21 ms | 6784 KB |
1_03.txt | AC | 21 ms | 6272 KB |
1_04.txt | AC | 18 ms | 5756 KB |
1_05.txt | AC | 18 ms | 5756 KB |
1_06.txt | AC | 18 ms | 5756 KB |
1_07.txt | AC | 18 ms | 5760 KB |
1_08.txt | AC | 18 ms | 5756 KB |
1_09.txt | AC | 13 ms | 5120 KB |
1_10.txt | AC | 18 ms | 5756 KB |
1_11.txt | AC | 16 ms | 5756 KB |
1_12.txt | AC | 18 ms | 5504 KB |
1_13.txt | AC | 18 ms | 5504 KB |
1_14.txt | AC | 16 ms | 5504 KB |
1_15.txt | AC | 18 ms | 5756 KB |
1_16.txt | AC | 17 ms | 5756 KB |
1_17.txt | AC | 17 ms | 5756 KB |
1_18.txt | AC | 18 ms | 5756 KB |
1_19.txt | AC | 18 ms | 5756 KB |
1_20.txt | AC | 18 ms | 5756 KB |
1_21.txt | AC | 18 ms | 5756 KB |
1_22.txt | AC | 18 ms | 5756 KB |
1_23.txt | AC | 18 ms | 5756 KB |
1_24.txt | AC | 16 ms | 5756 KB |
1_25.txt | AC | 18 ms | 5756 KB |
1_26.txt | AC | 17 ms | 5504 KB |
1_27.txt | AC | 18 ms | 5504 KB |
1_28.txt | AC | 16 ms | 5504 KB |
1_29.txt | AC | 16 ms | 5504 KB |
1_30.txt | AC | 18 ms | 5632 KB |
1_31.txt | AC | 18 ms | 5632 KB |
1_32.txt | AC | 18 ms | 5632 KB |
1_33.txt | AC | 18 ms | 5696 KB |
1_34.txt | AC | 18 ms | 5504 KB |
1_35.txt | AC | 18 ms | 5504 KB |
1_36.txt | AC | 16 ms | 5504 KB |
1_37.txt | AC | 16 ms | 5504 KB |
1_38.txt | AC | 18 ms | 5376 KB |
1_39.txt | AC | 18 ms | 5376 KB |
1_40.txt | AC | 16 ms | 5376 KB |
1_41.txt | AC | 15 ms | 5376 KB |
1_42.txt | AC | 19 ms | 5888 KB |
1_43.txt | AC | 20 ms | 5888 KB |
1_44.txt | AC | 19 ms | 5888 KB |
1_45.txt | AC | 20 ms | 5888 KB |
1_46.txt | AC | 20 ms | 5760 KB |
1_47.txt | AC | 19 ms | 5632 KB |
1_48.txt | AC | 18 ms | 5760 KB |
1_49.txt | AC | 18 ms | 5632 KB |
1_50.txt | AC | 20 ms | 5888 KB |
1_51.txt | AC | 19 ms | 5888 KB |
1_52.txt | AC | 19 ms | 5888 KB |
1_53.txt | AC | 20 ms | 5888 KB |