#include<bits/stdc++.h>
using namespace std;
const int N = 2000+1, mod = 1e9+7;
int n, i, j;
map<int, map<int, long long>> mp[N];
long long A[] = {1, 2, 16, 272, 7936}
long long f(int n, int i, int j){
if(j == 1)
return n == 1;
if(i == 1 && j == 2){
if((n&1) == 0)
return 0;
return A[(n-2)/2];
}
if(mp[n].find(i) != mp[n].end() && mp[n][i].find(j) != mp[n][i].end())
goto END;
if(i == 1){
if(n&1) mp[n][i][j] = f(n, 1, j-1) - f(n-1, 1, j-1);
else mp[n][i][j] = f(n, 1, j-1) + f(n-1, 1, j-1);
}
else if(i == 2)
mp[n][i][j] = f(n, 1, j) + f(n-1, 1, j-1);
else mp[n][i][j] = 2*f(n, i-1, j) - f(n, i-2, j) - f(n-2, i-2, j-2);
mp[n][i][j] %= mod;
END:
return mp[n][i][j];
}
int main(){
ios_base::sync_with_stdio(false);
cout.tie(0);
cin.tie(0);
cin >> n >> i >> j;
cout << f(n, i, j);
}
Compilation message
kangaroo.cpp:13:1: error: expected ',' or ';' before 'long'
13 | long long f(int n, int i, int j){
| ^~~~
kangaroo.cpp: In function 'int main()':
kangaroo.cpp:40:13: error: 'f' was not declared in this scope
40 | cout << f(n, i, j);
| ^
