#include<bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef long long ll;
#define int ll
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define pb push_back
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define mispertion ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define F first
#define S second
#define getlast(s) (*s.rbegin())
#define debg cout << "OK\n"
const ld PI = 3.1415926535;
const int N = 2e5 + 2;
const int M = 7e6 + 1;
int mod = 1e9+7;
const int infi = INT_MAX;
const ll infl = LLONG_MAX;
const int P = 31;
int mult(int a, int b) {
return a * 1LL * b % mod;
}
int sum(int a, int b) {
a %= mod;
if (a + b < 0)
return a + b + mod;
if (a + b >= mod)
return a + b - mod;
return a + b;
}
ll binpow(ll a, ll n) {
if (n == 0)
return 1;
if (n % 2 == 1) {
return binpow(a, n - 1) * a % mod;
} else {
ll b = binpow(a, n / 2);
return b * b % mod;
}
}
void solve(){
int n, cs, cf;
cin >> n >> cs >> cf;
int a[n + 1][n + 1][n + 1];
int pra[n + 1][n + 1][n + 1];
int sfa[n + 1][n + 1][n + 1];
int d[n + 1][n + 1][n + 1];
memset(a, 0, sizeof a);
memset(d, 0, sizeof d);
a[2][1][2] = 1;
d[2][2][1] = 1;
for(int i = 3; i <= n; i++){
for(int s = 1; s <= i; s++){
for(int f = 1; f <= i; f++){
if(s == f)
continue;
if(s > f){
a[i][s][f] = sum(a[i][s][f - 1], d[i - 1][s - 1][f - 1]);
d[i][s][f] = sum(d[i][s][f - 1], -a[i - 1][s - 1][f - 1]);
}
for(int f1 = 1; f1 < f; f1++){
if(s > f){
}else{
a[i][s][f] = sum(a[i][s][f], d[i - 1][s][f1]);
}
}
for(int f1 = f; f1 <= i; f1++){
if(s > f){
}else{
d[i][s][f] = sum(d[i][s][f], a[i - 1][s][f1]);
}
}
}
}
}
cout << sum(d[n][cs][cf], a[n][cs][cf]) << '\n';
}
signed main() {
mispertion;
int t = 1;
//cin >> t;
while(t--){
solve();
}
return 0;
}
Compilation message
kangaroo.cpp: In function 'void solve()':
kangaroo.cpp:59:9: warning: unused variable 'pra' [-Wunused-variable]
59 | int pra[n + 1][n + 1][n + 1];
| ^~~
kangaroo.cpp:60:9: warning: unused variable 'sfa' [-Wunused-variable]
60 | int sfa[n + 1][n + 1][n + 1];
| ^~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
