Submission #1797097

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Source Code Expand

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

const int MAX_N = 55, MOD = 1000000007;

int cnt[MAX_N << 1], N, tot;

int f[MAX_N][MAX_N << 1][MAX_N << 1];

int main() {
  scanf("%d", &N);
  for (int i = 1, A; i < N << 1; ++i) {
    scanf("%d", &A);
    cnt[A]++;
  }
  for (int i = 1; i < N << 1; ++i) {
    while (!cnt[i] && i < N << 1) i++;
    if (cnt[i]) cnt[++tot] = cnt[i];
  }
  
  for (int i = 1; i <= tot; ++i) cnt[i] += cnt[i - 1];
  
  int l = tot, r = 1, now;
  
  while (cnt[l - 1] >= N) l--;
  while (cnt[r] < N) r++;
  now = r - l + 1;

  f[N][1][1] = 1;
  for (int i = N - 1; i >= 1; --i) {
    int nl = 0, nr = 0;
    if (cnt[l - 1] >= i) l--, nl = 1;
    if (cnt[r] < 2 * N - i) r++, nr = 1;
    
    for (int j = 1; j <= tot; ++j)
      for (int k = 1; k <= j; ++k)
	if (f[i + 1][j][k]) {
	  int nk = k + nl, nj = j + nl + nr;
	  for (int x = 1; x <= nj; ++x)
	    (f[i][nj - (x - nk == 0 ? 0 : abs(x - nk) - 1)][x <= nk ? x : nk + 1] += f[i + 1][j][k]) %= MOD;
	}
  }

  int res = 0;
  for (int i = 1; i <= tot; ++i)
    for (int j = 1; j <= i; ++j)
      res = (res + f[1][i][j]) % MOD;
  printf("%d\n", res);
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:13:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &N);
                  ^
./Main.cpp:15:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &A);
                    ^

Judge Result