Submission #1276241

#TimeUsernameProblemLanguageResultExecution timeMemory
1276241hoa208Tents (JOI18_tents)C++20
0 / 100
919 ms218208 KiB
#include<bits/stdc++.h> using namespace std; #define ll long long #define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++) #define FORD(i, b, a) for (int i = (b), _a = (a); i >= _a; i--) #define pa pair<ll, ll> #define fi first #define se second #define bit(mask, j) ((mask >> j) & 1) const ll mod = 1e9 + 7; const ll INF = 1e18; //-------------------------------------------------------------------- ll n, m; const ll N = 303; ll f[N][N][N]; ll dp(ll i, ll j, ll k) { // if(j < 0) return 0; if(i == n + 1) { return 1; } if(f[i][j][k] != -1) return f[i][j][k]; ll res = 0; res += dp(i + 1, j, k); res %= mod; res += dp(i + 1, j - 1, k + 1) * j % mod; res %= mod; res += ((dp(i + 1, j - 1, k) * j % mod) + (dp(i + 1, j, k - 1) * k % mod)) % mod; res %= mod; res += (dp(i + 1, j - 1, k) * j % mod * 2) % mod; res %= mod; res += (dp(i + 1, j - 2, k) * (j * (j - 1) / 2)) % mod; res %= mod; return f[i][j][k] = res; } void hbmt() { memset(f, -1, sizeof f); cin >> n >> m; cout << (dp(1, m, 0) - 1 + mod) % mod; } int main() { ios_base::sync_with_stdio(0); cin.tie(0);cout.tie(0); #define NAME "hbmt" if(fopen(NAME".inp", "r")) { freopen(NAME".inp", "r", stdin); freopen(NAME".out", "w", stdout); } //int t;cin>>t;while(t--) hbmt(); return 0; }

Compilation message (stderr)

tents.cpp: In function 'int main()':
tents.cpp:48:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |         freopen(NAME".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
tents.cpp:49:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |         freopen(NAME".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
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