Submission #1772053

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Source Code Expand

#include<bits/stdc++.h>
#define mo 1000000007
#define add(a,b) (a+b>=mo)?(a+=b-mo):(a+=b)
using namespace std;
int a[110],f[55][110][110];
int main()
{
	int n;scanf("%d",&n);
	for (int i=1;i<2*n;i++) scanf("%d",&a[i]);
	sort(a+1,a+2*n);a[0]=a[1];a[2*n]=a[2*n-1];
	f[n][a[n]!=a[n-1]][a[n]!=a[n+1]]=1;
	for (int i=n;i>1;i--)
	for (int l=0;l<=2*n-1;l++)
	for (int r=0;r<=2*n-1;r++) if (f[i][l][r])
	{
		for (int k=0;k<l;k++) add(f[i-1][k+(a[i-2]!=a[i-1])][r+(a[2*n-i+1]!=a[2*n-i+2])+1],f[i][l][r]);
		add(f[i-1][l+(a[i-2]!=a[i-1])][r+(a[2*n-i+1]!=a[2*n-i+2])],f[i][l][r]);
		for (int k=0;k<r;k++) add(f[i-1][l+(a[i-2]!=a[i-1])+1][k+(a[2*n-i+1]!=a[2*n-i+2])],f[i][l][r]);
	}
	int ans=0;
	for (int l=0;l<=2*n-1;l++)
	for (int r=0;r<=2*n-1;r++) add(ans,f[1][l][r]);
	printf("%d\n",ans);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:8:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  int n;scanf("%d",&n);
                      ^
./Main.cpp:9:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  for (int i=1;i<2*n;i++) scanf("%d",&a[i]);
                                           ^

Judge Result