#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define all(aaa) aaa.begin(), aaa.end()
const int N = 205, MOD = 1e9 + 7;
int dp[N][N][N][2], pref[N][N][N][2];
void add(int &a, int b) {
a += b;
if (a >= MOD)
a -= MOD;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n, cs, cf;
cin >> n >> cs >> cf;
dp[2][2][1][1]++;
dp[2][1][2][0]++;
pref[2][2][1][1]++;
pref[2][2][2][1]++;
pref[2][1][2][0]++;
for (int i = 3; i <= n; i++) {
for (int k = 1; k <= i; k++) {
for (int j = k + 1; j <= i; j++) {
add(dp[i][k][j][0], pref[i - 1][k][j - 1][1]);
add(dp[i][k][j][1], pref[i - 1][k][i - 1][0]);
add(dp[i][k][j][1], MOD - pref[i - 1][k][j - 1][0]);
}
for (int j = 1; j < k; j++) {
dp[i][k][j][0] = dp[i][j][k][(i & 1) ^ 1];
dp[i][k][j][1] = dp[i][j][k][(i & 1)];
}
for (int j = 1; j <= i; j++) {
pref[i][k][j][0] = pref[i][k][j - 1][0];
pref[i][k][j][1] = pref[i][k][j - 1][1];
add(pref[i][k][j][0], dp[i][k][j][0]);
add(pref[i][k][j][1], dp[i][k][j][1]);
}
}
}
int ans = (dp[n][cf][cs][0] + dp[n][cf][cs][1]) % MOD;
cout << ans;
// for (int i = 1; i <= n; i++) {
// for (int j = 1; j <= n; j++) {
// cout << dp[n][i][j][0] << " ";
// }
// cout << "\n";
// }
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
384 KB |
Output is correct |
2 |
Correct |
6 ms |
512 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
384 KB |
Output is correct |
2 |
Correct |
6 ms |
512 KB |
Output is correct |
3 |
Correct |
5 ms |
1664 KB |
Output is correct |
4 |
Correct |
7 ms |
3200 KB |
Output is correct |
5 |
Correct |
6 ms |
3072 KB |
Output is correct |
6 |
Correct |
7 ms |
3200 KB |
Output is correct |
7 |
Correct |
6 ms |
2816 KB |
Output is correct |
8 |
Correct |
7 ms |
3072 KB |
Output is correct |
9 |
Correct |
7 ms |
3200 KB |
Output is correct |
10 |
Correct |
7 ms |
3200 KB |
Output is correct |
11 |
Correct |
7 ms |
3072 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
384 KB |
Output is correct |
2 |
Correct |
6 ms |
512 KB |
Output is correct |
3 |
Correct |
5 ms |
1664 KB |
Output is correct |
4 |
Correct |
7 ms |
3200 KB |
Output is correct |
5 |
Correct |
6 ms |
3072 KB |
Output is correct |
6 |
Correct |
7 ms |
3200 KB |
Output is correct |
7 |
Correct |
6 ms |
2816 KB |
Output is correct |
8 |
Correct |
7 ms |
3072 KB |
Output is correct |
9 |
Correct |
7 ms |
3200 KB |
Output is correct |
10 |
Correct |
7 ms |
3200 KB |
Output is correct |
11 |
Correct |
7 ms |
3072 KB |
Output is correct |
12 |
Correct |
63 ms |
65656 KB |
Output is correct |
13 |
Correct |
61 ms |
58108 KB |
Output is correct |
14 |
Correct |
63 ms |
65528 KB |
Output is correct |
15 |
Correct |
64 ms |
66296 KB |
Output is correct |
16 |
Correct |
63 ms |
65528 KB |
Output is correct |
17 |
Correct |
64 ms |
66168 KB |
Output is correct |
18 |
Correct |
52 ms |
52728 KB |
Output is correct |
19 |
Correct |
65 ms |
64248 KB |
Output is correct |
20 |
Correct |
65 ms |
66168 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
384 KB |
Output is correct |
2 |
Correct |
6 ms |
512 KB |
Output is correct |
3 |
Correct |
5 ms |
1664 KB |
Output is correct |
4 |
Correct |
7 ms |
3200 KB |
Output is correct |
5 |
Correct |
6 ms |
3072 KB |
Output is correct |
6 |
Correct |
7 ms |
3200 KB |
Output is correct |
7 |
Correct |
6 ms |
2816 KB |
Output is correct |
8 |
Correct |
7 ms |
3072 KB |
Output is correct |
9 |
Correct |
7 ms |
3200 KB |
Output is correct |
10 |
Correct |
7 ms |
3200 KB |
Output is correct |
11 |
Correct |
7 ms |
3072 KB |
Output is correct |
12 |
Correct |
63 ms |
65656 KB |
Output is correct |
13 |
Correct |
61 ms |
58108 KB |
Output is correct |
14 |
Correct |
63 ms |
65528 KB |
Output is correct |
15 |
Correct |
64 ms |
66296 KB |
Output is correct |
16 |
Correct |
63 ms |
65528 KB |
Output is correct |
17 |
Correct |
64 ms |
66168 KB |
Output is correct |
18 |
Correct |
52 ms |
52728 KB |
Output is correct |
19 |
Correct |
65 ms |
64248 KB |
Output is correct |
20 |
Correct |
65 ms |
66168 KB |
Output is correct |
21 |
Runtime error |
155 ms |
139372 KB |
Execution killed with signal 11 (could be triggered by violating memory limits) |
22 |
Halted |
0 ms |
0 KB |
- |