Submission #643277

#	Time	Username	Problem	Language	Result	Execution time	Memory
643277		valerikk	Tents (JOI18_tents)	C++17	100 / 100	116 ms	70720 KiB

tents

#include <cstdio>

#define MOD 1000000007

#define MAX 3003

long long dp[MAX][MAX];

int main() {
  int H, W;
  scanf("%d%d", &H, &W);

  dp[0][0] = 1;
  for (int w = 1; w <= W; ++w) {
    dp[0][w] = 1;
  }
  for (int h = 1; h <= H; ++h) {
    dp[h][0] = 1;
  }

  for (int h = 1; h <= H; ++h) {
    for (int w = 1; w <= W; ++w) {
      dp[h][w] = (dp[h][w] + dp[h - 1][w]) % MOD;
      
      if (w >= 2)
        dp[h][w] = (dp[h][w] + w * 1LL * (w - 1) / 2 % MOD * dp[h - 1][w - 2]) % MOD;

      dp[h][w] = (dp[h][w] + w * 4 * dp[h - 1][w - 1]) % MOD;

      if (h >= 2)
        dp[h][w] = (dp[h][w] + w * 1LL * (h - 1) * dp[h - 2][w - 1]) % MOD;
    }
  }

  printf("%lld\n", (dp[H][W] - 1 + MOD) % MOD);
}

Compilation message (stderr)

tents.cpp: In function 'int main()':
tents.cpp:11:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |   scanf("%d%d", &H, &W);
      |   ~~~~~^~~~~~~~~~~~~~~~

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