Submission #729007

#	Time	Username	Problem	Language	Result	Execution time	Memory
729007		nguyentunglam	Tents (JOI18_tents)	C++17	100 / 100	147 ms	35636 KiB

tents

#include<bits/stdc++.h>
#define fi first
#define se second
#define endl "\n"
#define ii pair<int, int>
//#define int long long
using namespace std;
const int mod = 1e9 + 7, N = 3000;
int f[N + 10][N + 10], C[N + 10][N + 10], g[N + 10];
void add(int &a, int b) {
    a += b;
    if (a >= mod) a -= mod;
}

main() {
    #define task ""
    cin.tie(0) -> sync_with_stdio(0);
    if (fopen ("task.inp", "r")) {
        freopen ("task.inp", "r", stdin);
        freopen ("task.out", "w", stdout);
    }
    if (fopen (task".inp", "r")) {
        freopen (task".inp", "r", stdin);
        freopen (task".out", "w", stdout);
    }
    int h, w; cin >> h >> w;
    for(int i = 0; i <= w; i++) f[0][i] = 1;
    for(int i = 0; i < h; i++) for(int j = 0; j <= w; j++) {
        add(f[i + 1][j], f[i][j]);
        add(f[i + 1][j + 1], 1LL * f[i][j] * (j + 1) % mod * 4 % mod);
        add(f[i + 2][j + 1], 1LL * f[i][j] * (i + 1) % mod * (j + 1) % mod);
        add(f[i + 1][j + 2], 1LL * f[i][j] * (1LL * (j + 2) * (j + 1) / 2 % mod) % mod);
    }
    cout << (f[h][w] - 1 + mod) % mod;
}

Compilation message (stderr)

tents.cpp:15:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   15 | main() {
      | ^~~~
tents.cpp: In function 'int main()':
tents.cpp:19:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |         freopen ("task.inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
tents.cpp:20:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |         freopen ("task.out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
tents.cpp:23:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   23 |         freopen (task".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
tents.cpp:24:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |         freopen (task".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 48 / 48
• Subtask 2: 52 / 52