#include <iostream>
#include <cstring>
using namespace std;
const int maxN = 210;
int m[maxN][maxN][maxN][4];
//cf shows the number of things before finish tile
int solve(int before, int after, int cf, int dir){
// cout << before << " " << after << " " << cf << " " << dir << endl;
if(after+before==1){
if(dir==1&&cf==0&&after==1){
//so we hop to second to last cell, the back to first cell
return 1;
} else if(dir==-1&&cf==1&&before==1){
//we hop to second to last cell, then forward to finish cell
return 1;
} else {
return 0;
}
}
if(m[before][after][cf][dir+2]!=-1){
return m[before][after][cf][dir+2];
}
m[before][after][cf][dir+2] = 0;
if(dir==-1||dir==0){
//must go backwards, towards 0
int z = cf;
for(int x=before-1, y=after; x>=0; x--, y++){
if(x<cf)
z = cf-1;
m[before][after][cf][dir+2] += solve(x, y, z, 1);
}
}
if(dir==1||dir==0){
//must go forward
int z = cf;
for(int x=after-1, y=before; x>=0; x--, y++){
if(y<cf)
z = cf-1;
m[before][after][cf][dir+2] += solve(y, x, z, -1);
}
}
return m[before][after][cf][dir+2];
}
int main(){
int N, cs, cf;
cin>>N>>cs>>cf;
if(N<=3){
cout << 1 << endl;
return 0;
}
memset(m, -1, sizeof(m));
int bef = cs-1, aft = N-cs;
if(cf>cs)
aft--;
else
bef--;
int cz = cf-1;
if(cs<cf){
cz--;
}
cout << solve(bef, aft, cz, 0) << endl;
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
104 ms |
145280 KB |
Output is correct |
| 2 |
Incorrect |
105 ms |
145388 KB |
Output isn't correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
104 ms |
145280 KB |
Output is correct |
| 2 |
Incorrect |
105 ms |
145388 KB |
Output isn't correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
104 ms |
145280 KB |
Output is correct |
| 2 |
Incorrect |
105 ms |
145388 KB |
Output isn't correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
104 ms |
145280 KB |
Output is correct |
| 2 |
Incorrect |
105 ms |
145388 KB |
Output isn't correct |
