Submission #4023091

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Source Code Expand

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cstdlib>
#include <queue>
using namespace std;
#define N 2050
#define mod 1000000007
typedef long long ll;
int n,m,K;
ll f[N<<1][N][2],s[N],ans;
void upd(ll &x,ll y) {
	x=x+y; if(x>=mod) x-=mod;
	if(x<0) x+=mod;
}
int main() {
	scanf("%d%d%d",&n,&m,&K);
	int t1=n%(K-1),t2=m%(K-1);
	f[0][0][0]=1;
	int i,j,lim=max(n,m)<<1;
	for(i=1;i<=lim;i++) {
		int num=i*(K-1);
		s[0]=(f[i-1][0][0]+f[i-1][0][1])%mod;
		for(j=1;j<=n;j++) {
			s[j]=(s[j-1]+f[i-1][j][0]+f[i-1][j][1])%mod;
		}
		for(j=0;j<=n;j++) {
			f[i][j][0]=(f[i-1][j][0]+f[i-1][j][1])%mod;
			if(j) f[i][j][1]=(s[j-1]-(j-K>=0?s[j-K]:0))%mod;
		}
		for(j=0;j<=n;j++) {
			if(j%(K-1)==t1 && (num-j+1)%(K-1)==t2 && num-j+1<=m) upd(ans,f[i][j][1]);
		}
	}
	printf("%lld\n",(ans+mod)%mod);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:17:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d",&n,&m,&K);
                          ^

Judge Result