Submission #370924

#	Time	Username	Problem	Language	Result	Execution time	Memory
370924		mjhmjh1104	Tents (JOI18_tents)	C++14	100 / 100	503 ms	36076 KiB

tents

#include <cstdio>
#include <algorithm>
using namespace std;

const int MOD = 1e9 + 7;

int dp[3006][3006];

int f(int x, int y) {
    if (dp[x][y] + 1) return dp[x][y];
    if (!x || !y) return dp[x][y] = 1;
    if (x == 1) return dp[x][y] = (1 + 4LL * y % MOD + 1LL * y * (y - 1) / 2 % MOD) % MOD;
    if (y == 1) return dp[x][y] = (1 + 4LL * x % MOD + 1LL * x * (x - 1) / 2 % MOD) % MOD;
    return dp[x][y] = (f(x, y - 1) + 4LL * x % MOD * f(x - 1, y - 1) + 1LL * x * (y - 1) % MOD * f(x - 1, y - 2) % MOD + 1LL * x * (x - 1) / 2 % MOD * f(x - 2, y - 1) % MOD) % MOD;
}

int h, w;

int main() {
    fill(dp[0], dp[3005] + 3006, -1);
    scanf("%d%d", &h, &w);
    printf("%d", (f(h, w) + MOD - 1) % MOD);
}

Compilation message (stderr)

tents.cpp: In function 'int main()':
tents.cpp:21:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   21 |     scanf("%d%d", &h, &w);
      |     ~~~~~^~~~~~~~~~~~~~~~

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