제출 #869129

#제출 시각아이디문제언어결과실행 시간메모리
869129mgl_diamond캥거루 (CEOI16_kangaroo)C++17
6 / 100
0 ms348 KiB
#include <bits/stdc++.h> using namespace std; using ll = long long; using ii = pair<int, int>; #define foru(i, l, r) for(int i=(l); i<=(r); ++i) #define ford(i, l, r) for(int i=(l); i>=(r); --i) #define fore(x, v) for(auto &x : v) #define all(x) (x).begin(), (x).end() #define sz(x) (int)(x).size() #define fi first #define se second #define file "input" void setIO() { ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); if (fopen(file".inp", "r")) { freopen(file".inp", "r", stdin); freopen(file".out", "w", stdout); } } const int N = 2002, MOD = 1e9+7; int n, s, t, f[N][N][2][2]; int ans; void add(int &a, int b) { a += b; if (a >= MOD) a -= MOD; } int mul(int a, int b) { return 1LL * a * b % MOD; } int nc2(int n) { return (n * (n-1) / 2) % MOD; } int main() { setIO(); cin >> n >> s >> t; f[0][0][0][0] = 1; foru(i, 0, n-1) foru(cc0, 0, i) foru(cc1, 0, 1) foru(cc2, 0, 1) { int ret = f[i][cc0][cc1][cc2]; if (ret == 0) continue; // cout << i << " " << cc0 << " " << cc1 << " " << cc2 << " " << ret << "\n"; if (i+1 == s) { add(f[i+1][cc0][1][cc2], ret); if (cc0 > 0) add(f[i+1][cc0-1][1][cc2], mul(ret, cc0)); continue; } if (i+1 == t) { add(f[i+1][cc0][cc1][1], ret); if (cc0 > 0) add(f[i+1][cc0-1][cc1][1], mul(ret, cc0)); continue; } add(f[i+1][cc0+1][cc1][cc2], ret); if (cc0 > 1) add(f[i+1][cc0-1][cc1][cc2], mul(mul(cc0, cc0-1), ret)); if (cc1 && cc0 > 0) add(f[i+1][cc0-1][cc1][cc2], mul(ret, cc0)); if (cc2 && cc0 > 0) add(f[i+1][cc0-1][cc1][cc2], mul(ret, cc0)); } cout << f[n-1][0][1][1]; }

컴파일 시 표준 에러 (stderr) 메시지

kangaroo.cpp: In function 'void setIO()':
kangaroo.cpp:19:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |     freopen(file".inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
kangaroo.cpp:20:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |     freopen(file".out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
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