(UPD: 2024-12-04 14:48 UTC) Judge is not working due to Cloudflare incident. (URL) We can do nothing about it, sorry. After the incident is resolved, we will grade all submissions.

Submission #59105

#TimeUsernameProblemLanguageResultExecution timeMemory
59105gabrielsimoesKangaroo (CEOI16_kangaroo)C++17
100 / 100
115 ms32340 KiB
#include <bits/stdc++.h> using namespace std; typedef long long ll; const int MAXN = 2000; const ll MOD = 1000000007; int n, cs, cf; ll dp[MAXN][MAXN]; ll f(int i, int k) { if (k < 0) return 0; if (i == n-1) return k == 0 ? 1 : 0; ll &ret = dp[i][k]; if (ret != -1) return ret; ret = 0; ll ks = i > cs; ll kf = i > cf; if (i == cs || i == cf) { ret += f(i+1, k); ret += f(i+1, k-1) * k; } else { ret += f(i+1, k+1); ret += f(i+1, k-1) * (k*(k-1) + ks*k + k*kf); } return ret %= MOD; } int main() { memset(dp, -1, sizeof(dp)); scanf("%d %d %d", &n, &cs, &cf); cs--; cf--; printf("%d\n", f(0, 0)); }

Compilation message (stderr)

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:38:24: warning: format '%d' expects argument of type 'int', but argument 2 has type 'll {aka long long int}' [-Wformat=]
  printf("%d\n", f(0, 0));
                 ~~~~~~~^
kangaroo.cpp:35:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %d", &n, &cs, &cf);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...