Submission #1693330

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

const int mo=int(1e9+7);
int n,k,f[2010][2010][2],ans;

void work()
{
	scanf("%d %d",&n,&k);
	f[0][0][1]=1;
	for (int i=0; i<n; i++)
		for (int j=i; ~j; j--)
			{
				f[i][j][1]=(f[i][j][1]+f[i][j][0])%mo;
				if (j)  f[i][j-1][0]=(f[i][j-1][0]+f[i][j][0])%mo;
				f[i+1][j][0]=(f[i+1][j][0]+f[i][j][1])%mo;
				f[i+1][j+1][1]=(f[i+1][j+1][1]+f[i][j][1])%mo;				
			}
	ans=f[n][n-k][0];
	for (int i=1; i<=n-k-1; i++)  ans=2*ans%mo;
	printf("%d",ans);
}

int main()
{
	work();
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘void work()’:
./Main.cpp:9:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n,&k);
                      ^

Judge Result