Submission #2203328

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Source Code Expand

#include <cstdio>
#include <algorithm>
using namespace std;
#define ref(i,x,y)for(int i=x;i<=y;++i)
#define def(i,x,y)for(int i=x;i>=y;--i)
const int mod=1e9+7;
void inc(int&a,int b){
	a+=b;if(a>=mod)a-=mod;
}
void dec(int&a,int b){
	a-=b;if(a<0)a+=mod;
}
int n,ans,a[100],f[100][100][51][51],g[100][100][51][51],h[51][51],h1[51][51],h2[201][102][102],h3[201][102][102];bool b[100];
int main(){
	freopen("1.in","r",stdin);
	scanf("%d",&n);
	ref(i,1,2*n-1)scanf("%d",&a[i]);
	sort(a+1,a+2*n);
	ref(i,1,n-1)if(a[i+1]!=a[i])b[i]=1;b[n]=1;
	ref(i,n+1,2*n-1)if(a[i-1]!=a[i])b[i]=1;
	f[n][n][1][1]=1;
	def(ti,n,2){
		ref(j,0,2*n)ref(I,1,n-ti+2)ref(J,1,I)h3[j][I][J]=0;
		def(i,2*n-1,ti){
			ref(j,i-1,2*n-ti+1)
				ref(I,1,n-ti+2)ref(J,1,I)
					h2[j][I][J]=0;
			ref(j,i,2*n-ti)if(b[i]&&b[j]){
				ref(I,1,n-ti+2)ref(J,1,I)h[I][J]=0,h1[I][J]=0;
				ref(t,1,n-ti+1)ref(k,1,t)if(f[i][j][t][k]){
					int s=f[i][j][t][k];
					inc(h[t-k+2][1],s), dec(h[t+1][k],s);
					if(k+1<=t) inc(h1[k+1][k+1],s), dec(h1[t+1][k+1],s);
					inc(h1[t][k],s), dec(h1[t+1][k],s);
					inc(h3[j][t-k+2][1],s); 
					if(j<=2*n-ti) inc(h2[j+1][k+1][k+1],s), dec(h2[2*n-ti+2][k+1][k+1],s);
				}
				ref(I,1,n-ti+2)ref(J,1,I){
					inc(h[I][J],h[I-1][J-1]); inc(h1[I][J],h1[I-1][J]);
					inc(g[i][j][I][J],h[I][J]);
					inc(g[i][j][I][J],h1[I][J]);
				}
			}
			if(b[i-1])ref(j,i,2*n-ti)
				ref(t,1,n-ti+2)ref(k,1,t){
					inc(g[i-1][j][t][k],h3[j][t][k]);
				}
			ref(j,i,2*n-ti+1)
				ref(I,1,n-ti+2)ref(J,1,I){
					inc(h2[j][I][J],h2[j-1][I][J]);
					if(b[i]&&b[j])inc(g[i][j][I][J],h2[j][I][J]);
				}
		}
		ref(i,1,2*n-1)ref(j,1,2*n-1)if(b[i]&&b[j])
			ref(t,1,n-ti+2)ref(k,1,t)
				f[i][j][t][k]=g[i][j][t][k],g[i][j][t][k]=0;
	}
	ref(i,1,2*n-1)ref(j,i,2*n-1)ref(t,1,n)ref(k,1,t)
		inc(ans,f[i][j][t][k]);
	printf("%d\n",ans);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:15:27: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
  freopen("1.in","r",stdin);
                           ^
./Main.cpp:16:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
./Main.cpp:17:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  ref(i,1,2*n-1)scanf("%d",&a[i]);
                                 ^

Judge Result