//#include <bits/stdc++.h>
#include <sstream>
#include<limits.h>
#include <queue>
#include <deque>
#include <stack>
#include <set>
#include <map>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <complex>
#include <cmath>
#include <iostream>
#include <iomanip>
#include <string>
#include <utility>
#include <vector>
#include <algorithm>
#include <bitset>
#include <list>
#include <string.h>
#include <assert.h>
#include <time.h>
#include <fstream>
#include <numeric>
#include <cstring>
using namespace std;
template<class T1> void deb(T1 e1)
{
cout<<e1<<endl;
}
template<class T1,class T2> void deb(T1 e1,T2 e2)
{
cout<<e1<<" "<<e2<<endl;
}
template<class T1,class T2,class T3> void deb(T1 e1,T2 e2,T3 e3)
{
cout<<e1<<" "<<e2<<" "<<e3<<endl;
}
template<class T1,class T2,class T3,class T4> void deb(T1 e1,T2 e2,T3 e3,T4 e4)
{
cout<<e1<<" "<<e2<<" "<<e3<<" "<<e4<<endl;
}
template<class T1,class T2,class T3,class T4,class T5> void deb(T1 e1,T2 e2,T3 e3,T4 e4,T5 e5)
{
cout<<e1<<" "<<e2<<" "<<e3<<" "<<e4<<" "<<e5<<endl;
}
template<class T1,class T2,class T3,class T4,class T5,class T6> void deb(T1 e1,T2 e2,T3 e3,T4 e4,T5 e5,T6 e6)
{
cout<<e1<<" "<<e2<<" "<<e3<<" "<<e4<<" "<<e5<<" "<<e6<<endl;
}
#define pb push_back
#define pp pop_back
#define pi 2*acos(0.0)
#define pf printf
#define sf scanf
#define EPS 1e-10
#define clr(a) memset(a,0,sizeof(a))
#define full(a) memset(a,63,sizeof(a))
#define max3(a,b,c) max(a,max(b,c))
#define min3(a,b,c) min(a,min(b,c))
#define sf1(a) scanf("%d",&a)
#define sf2(a,b) scanf("%d%d",&a,&b)
#define sf3(a,b,c) scanf("%d%d%d",&a,&b,&c)
#define sf1ll(a) scanf("%lld",&a)
#define sf2ll(a,b) scanf("%lld%lld",&a,&b)
#define sf3ll(a,b,c) scanf("%lld%lld%lld",&a,&b,&c)
#define sf1d(a) scanf("%lf",&a)
#define sf2d(a,b) scanf("%lf%lf",&a,&b)
#define sf3d(a,b,c) scanf("%lf%lf%lf",&a,&b,&c)
#define READ(in) freopen("in.txt","r",stdin);
#define WRITE(out) freopen("out.txt","w",stdout);
#define _boost ios_base::sync_with_stdio(0); cin.tie(0);
#define sr_pr(s1) printf("%s",s1.c_str())
#define fo(i,n) for(i=0;i<n;i++)
#define mp make_pair
#define MAX
#define MOD
typedef long long ll;
typedef unsigned long long ull;
//bitmask
/*int Set( int n, int pos ){
return n = n|( 1<<pos );
}
bool check( int n, int pos ){
return (bool)( n&( 1LL<<pos ) );
}
int reset( int n, int pos ){
return n = n&~( 1<<pos );
}*/
/*BIGMOD
ll big_mod(ll a,ll b,ll m)
{
long long int i,j,k,l; if(b==0) return 1;
if(b%2==0){ k=big_mod(a,b/2,m); return ((k%m)*(k%m))%m;}
else return((a%m)*(big_mod(a,b-1,m))%m)%m;
}
/*GCD
int gcd(int a,int b){ if(b==0) return a; return gcd(b,a%b);}
/*PARENT_FIND
int pfind(int r) return par[r]==r ? r : par[r]=pfind(par[r]);
}*/
/*BASE_CONVERT
int convert_base_big_TO_small(int num,int base,int ar1[])
{
if(num==0) {ar1[0]=0;return 1;}
int ar2[110],l=0;
while(1) { if(num<base) break; ar2[l++]=num%base; num/=base; }
if(num>0) ar2[l++]=num;
for(int i=0;i<l;i++) { ar1[i]=ar2[l-i-1]; } return l;
}
int convert_base_small_TO_big(int ar1[],int base,int len)
{
int pw[110],i,j,k; pw[0]=1;
for(i=1;i<=len+1;i++) { pw[i]=pw[i-1]*2;//for 2 base to 10 base }
int sum=0,l=0;
for(i=len-1;i>=0;i--) { sum+=(ar1[l++]*pw[i]);//deb(sum); }
return sum;
}
*/
int dx[]= {0,0,1,-1};
int dy[]= {-1,1,0,0};
//int dx[]= {1,-1,0,0,-1,-1,1,1};/*8 move*/
//int dy[]= {0,0,1,-1,1,-1,1,-1};/*8 move*/
//int dx[]={1,1,2,2,-1,-1,-2,-2};/*knight move*/
//int dy[]={2,-2,1,-1,2,-2,1,-1};/*knight move*/
#define MXK 450000
#define mx 400000
#define fs first
#define sc second
#define ll long long
#define mod 1000000007
typedef pair< long long, long long>pii;
ll dp[2005][2005][3][3];
int n,s,e;
ll dp_func(int pos,int com,int st,int en)
{
if(com<0)return 0;
if(pos==n+1){
if(pos==s){
return com==0;
}
if(pos==e){
return com==0;
}
return com==0;
}
if(dp[pos][com][st][en]!=-1)return dp[pos][com][st][en];
ll& ret=dp[pos][com][st][en];
ret=0;
if(pos==s){
if(com)ret+=dp_func(pos+1,com-1,1,en)*com;
ret+=dp_func(pos+1,com,1,en);
ret%=mod;
return ret;
}
if(pos==e){
if(com)ret+=dp_func(pos+1,com-1,st,1)*com;
// if(com)cout<<ret<<endl;
ret+=dp_func(pos+1,com,st,1);
ret%=mod;
return ret;
}
ret+=dp_func(pos+1,com-1,st,en)*(com*(com-1));
ret+=dp_func(pos+1,com+1,st,en);
if(st&&com)ret+=dp_func(pos+1,com-1,st,en)*com;
if(en&&com)ret+=dp_func(pos+1,com-1,st,en)*com;
ret%=mod;
return ret;
}
int main()
{
//READ(kangaroo);
// WRITE(kangaroo);
int i,j,k,l,m;
scanf("%d%d%d",&n,&s,&e);
memset(dp,-1,sizeof dp);
ll ans=dp_func(1,0,0,0);
cout<<ans<<endl;
}
Compilation message
kangaroo.cpp:103:1: warning: "/*" within comment [-Wcomment]
/*GCD
^
kangaroo.cpp:106:1: warning: "/*" within comment [-Wcomment]
/*PARENT_FIND
^
kangaroo.cpp: In function 'int main()':
kangaroo.cpp:183:8: warning: unused variable 'i' [-Wunused-variable]
int i,j,k,l,m;
^
kangaroo.cpp:183:10: warning: unused variable 'j' [-Wunused-variable]
int i,j,k,l,m;
^
kangaroo.cpp:183:12: warning: unused variable 'k' [-Wunused-variable]
int i,j,k,l,m;
^
kangaroo.cpp:183:14: warning: unused variable 'l' [-Wunused-variable]
int i,j,k,l,m;
^
kangaroo.cpp:183:16: warning: unused variable 'm' [-Wunused-variable]
int i,j,k,l,m;
^
kangaroo.cpp:184:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d%d",&n,&s,&e);
^
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
204 ms |
283640 KB |
Output is correct |
| 2 |
Incorrect |
204 ms |
283664 KB |
Output isn't correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
204 ms |
283640 KB |
Output is correct |
| 2 |
Incorrect |
204 ms |
283664 KB |
Output isn't correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
204 ms |
283640 KB |
Output is correct |
| 2 |
Incorrect |
204 ms |
283664 KB |
Output isn't correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
204 ms |
283640 KB |
Output is correct |
| 2 |
Incorrect |
204 ms |
283664 KB |
Output isn't correct |
