#include <bits/stdc++.h>
using namespace std;
const int N =3005,mod = 1e9+7;
#define ll long long
ll per[N];
ll mypow(ll x,ll c){
ll ret=1;
while(c){
if(c&1)
ret= (ret*x)%mod;
x = (x*x)%mod;
c>>=1;
}
return ret;
}
int dp[N][N];
int solve(int x,int y,int lx,int ly,int a,int b){
if(x==lx && ly==y)return 1;
int &ret= dp[x][y];
if(ret!=-1)return ret;
ret = 0;
if(y<ly){
ll temp = a+x;
temp = per[temp];
ret = (ret + (temp*solve(x,y+1,lx,ly,a,b))%mod)%mod;
}
if(x<lx){
ll temp = b+y;
temp = per[temp];
ret= (ret + (temp*solve(x+1,y,lx,ly,a,b) )%mod )%mod;
}
return ret;
}
ll combi(int n,int c){
ll ret= per[n];
ret = (ret *mypow(per[c],mod-2))%mod;
ret = (ret *mypow(per[n-c],mod-2))%mod;
return ret;
}
int main(){
//freopen("input.txt","r",stdin);
per[0]= 1;
for(int i=1;i<N;++i)per[i]=(per[i-1]*i)%mod;
memset(dp,-1,sizeof(dp));
int dx=N,dy =N,ux=0,uy = 0;
int r,c,n;
cin>>r>>c>>n;
if(r>=N || c>=N){
cout<<"FUCKING MEMORY\n";
assert(0);
}
for(int i=0;i<n;++i){
int u,v;
cin>>u>>v;
dx= min(dx,u),dy= min(dy,v);
ux= max(ux,u),uy= max(uy,v);
}
int a = ux-dx+1;
int b= uy-dy+1;
int tot = a*b - n;
ll ret = per[tot];
ret = (ret * combi(r-a,dx-1))%mod;
ret = (ret*combi(c-b,dy-1))%mod;
ret= (ret * solve(0,0,r-a,c-b,a,b))%mod;
cout<<ret<<endl;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
30 ms |
35708 KB |
Output is correct |
2 |
Correct |
28 ms |
35804 KB |
Output is correct |
3 |
Correct |
27 ms |
35804 KB |
Output is correct |
4 |
Correct |
27 ms |
35836 KB |
Output is correct |
5 |
Correct |
29 ms |
35884 KB |
Output is correct |
6 |
Correct |
28 ms |
35980 KB |
Output is correct |
7 |
Correct |
28 ms |
35980 KB |
Output is correct |
8 |
Correct |
28 ms |
35980 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
29 ms |
35980 KB |
Output is correct |
2 |
Correct |
29 ms |
35980 KB |
Output is correct |
3 |
Correct |
29 ms |
35980 KB |
Output is correct |
4 |
Correct |
26 ms |
35980 KB |
Output is correct |
5 |
Correct |
27 ms |
35980 KB |
Output is correct |
6 |
Correct |
28 ms |
35980 KB |
Output is correct |
7 |
Correct |
29 ms |
35980 KB |
Output is correct |
8 |
Correct |
27 ms |
35980 KB |
Output is correct |
9 |
Correct |
28 ms |
35980 KB |
Output is correct |
10 |
Correct |
28 ms |
35980 KB |
Output is correct |
11 |
Correct |
29 ms |
35980 KB |
Output is correct |
12 |
Correct |
31 ms |
35980 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
27 ms |
35980 KB |
Output is correct |
2 |
Runtime error |
66 ms |
71400 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
3 |
Halted |
0 ms |
0 KB |
- |