Submission #3049647
Source Code Expand
#include<cstdio>
#define neko 5010
#define seko 1000010
#define f(i,a,b) for(register int i=(a);i<=(b);i=-(~(i)))
#define rf(i,a,b) for(register int i=(a);i>=(b);i=~(-(i)))
int n,a[seko],b[seko];
typedef long long ll;
ll dp[neko][neko],fac[seko],invfac[seko],ans,mod=1e9+7;
ll slowpow(ll m,ll n)
{
ll b=1;
for(;n;n>>=1,m=m*m%mod)if(n&1)b=b*m%mod;
return b;
}
ll C(ll m,ll n)
{if(n>m)return 0;return fac[m]*invfac[n]%mod*invfac[m-n]%mod;}
ll ADD(ll x,ll y){return (x+=y)>=mod?x-mod:x;}
int main()
{
scanf("%d",&n);
f(i,1,n)scanf("%d%d",&a[i],&b[i]),++dp[-a[i]+2000][-b[i]+2000];
fac[0]=invfac[0]=1;
f(i,1,10000)fac[i]=fac[i-1]*i%mod;
invfac[10000]=slowpow(fac[10000],mod-2);
rf(i,9999,1)invfac[i]=invfac[i+1]*(i+1)%mod;
f(i,0,4000)
f(j,0,4000)
{
if(i)dp[i][j]=ADD(dp[i][j],dp[i-1][j]);
if(j)dp[i][j]=ADD(dp[i][j],dp[i][j-1]);
}
f(i,1,n)ans=(ans+dp[a[i]+2000][b[i]+2000])%mod;
f(i,1,n)ans=(ans+mod-C(2*(a[i]+b[i]),2*a[i]))%mod;
printf("%lld\n",(ans*slowpow(2,mod-2)%mod+mod)%mod);
}
Submission Info
Submission Time
2018-08-20 21:19:54+0900
Task
E - BBQ Hard
User
colldisSavior
Language
C++14 (GCC 5.4.1)
Score
1400
Code Size
1037 Byte
Status
AC
Exec Time
149 ms
Memory
166144 KB
Compile Error
./Main.cpp: In function ‘int main()’:
./Main.cpp:20:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
scanf("%d",&n);
^
./Main.cpp:21:64: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
f(i,1,n)scanf("%d%d",&a[i],&b[i]),++dp[-a[i]+2000][-b[i]+2000];
^
Judge Result
Set Name
Sample
All
Score / Max Score
0 / 0
1400 / 1400
Status
Set Name
Test Cases
Sample
sample-01.txt
All
sample-01.txt, 01-01.txt, 01-02.txt, 01-03.txt, 01-04.txt, 01-05.txt, 01-06.txt, 01-07.txt, 01-08.txt, 01-09.txt, 01-10.txt, 01-11.txt, 01-12.txt, 01-13.txt, 01-14.txt, sample-01.txt
Case Name
Status
Exec Time
Memory
01-01.txt
AC
93 ms
165376 KB
01-02.txt
AC
89 ms
166144 KB
01-03.txt
AC
118 ms
166144 KB
01-04.txt
AC
149 ms
166144 KB
01-05.txt
AC
149 ms
166144 KB
01-06.txt
AC
126 ms
166144 KB
01-07.txt
AC
86 ms
166144 KB
01-08.txt
AC
120 ms
166144 KB
01-09.txt
AC
126 ms
166144 KB
01-10.txt
AC
134 ms
166144 KB
01-11.txt
AC
136 ms
166144 KB
01-12.txt
AC
128 ms
166144 KB
01-13.txt
AC
145 ms
166144 KB
01-14.txt
AC
146 ms
166144 KB
sample-01.txt
AC
86 ms
166144 KB