QOJ.ac
QOJ
| ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
|---|---|---|---|---|---|---|---|---|---|
| #31176 | #2573. Two Permutations | leeh18 | AC ✓ | 268ms | 11448kb | C++20 | 1.3kb | 2022-05-04 02:51:11 | 2022-05-04 02:51:12 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
const int mod = 1000000007;
int dp[2][101][10001];
int main() {
cin.tie(0)->sync_with_stdio(0);
int n, m;
cin >> n >> m;
dp[0][0][0] = 1;
for (int i = 1; i <= n; i++) {
for (int j = 0; j <= i; j++) {
for (int k = 0; k <= m; k++) {
dp[i&1][j][k] = 0;
if (n-2*i+j+2 >= 2) {
dp[i&1][j][k] += (long long)dp[(i&1)^1][j][k] * (n-2*i+j+2) * (n-2*i+j+1) % mod;
if (dp[i&1][j][k] >= mod) {
dp[i&1][j][k] -= mod;
}
}
if (j >= 1 && k >= i && (n-2*i+j+1) >= 0) {
dp[i&1][j][k] += (long long)dp[(i&1)^1][j-1][k-i] * (n-2*i+j+1) * (2*i-2*j+1) % mod;
if (dp[i&1][j][k] >= mod) {
dp[i&1][j][k] -= mod;
}
}
if (j >= 2 && k >= 2*i && i-j+1 >= 0) {
dp[i&1][j][k] += (long long)dp[(i&1)^1][j-2][k-2*i] * (i-j+1) * (i-j+1) % mod;
if (dp[i&1][j][k] >= mod) {
dp[i&1][j][k] -= mod;
}
}
}
}
}
cout << dp[n&1][n][m] << '\n';
return 0;
}
详细
Test #1:
score: 100
Accepted
time: 3ms
memory: 5656kb
input:
2 4
output:
2
result:
ok 1 number(s): "2"
Test #2:
score: 0
Accepted
time: 3ms
memory: 5608kb
input:
3 7
output:
12
result:
ok 1 number(s): "12"
Test #3:
score: 0
Accepted
time: 3ms
memory: 5732kb
input:
4 10
output:
24
result:
ok 1 number(s): "24"
Test #4:
score: 0
Accepted
time: 1ms
memory: 5716kb
input:
4 14
output:
96
result:
ok 1 number(s): "96"
Test #5:
score: 0
Accepted
time: 3ms
memory: 5676kb
input:
5 10
output:
0
result:
ok 1 number(s): "0"
Test #6:
score: 0
Accepted
time: 3ms
memory: 7648kb
input:
5 15
output:
120
result:
ok 1 number(s): "120"
Test #7:
score: 0
Accepted
time: 3ms
memory: 5692kb
input:
5 21
output:
2400
result:
ok 1 number(s): "2400"
Test #8:
score: 0
Accepted
time: 0ms
memory: 5760kb
input:
6 21
output:
720
result:
ok 1 number(s): "720"
Test #9:
score: 0
Accepted
time: 3ms
memory: 5612kb
input:
6 30
output:
25920
result:
ok 1 number(s): "25920"
Test #10:
score: 0
Accepted
time: 3ms
memory: 5660kb
input:
6 27
output:
106560
result:
ok 1 number(s): "106560"
Test #11:
score: 0
Accepted
time: 1ms
memory: 7796kb
input:
20 300
output:
644873710
result:
ok 1 number(s): "644873710"
Test #12:
score: 0
Accepted
time: 4ms
memory: 7800kb
input:
20 139
output:
0
result:
ok 1 number(s): "0"
Test #13:
score: 0
Accepted
time: 5ms
memory: 7720kb
input:
30 470
output:
491424690
result:
ok 1 number(s): "491424690"
Test #14:
score: 0
Accepted
time: 2ms
memory: 7984kb
input:
30 500
output:
8436035
result:
ok 1 number(s): "8436035"
Test #15:
score: 0
Accepted
time: 4ms
memory: 5968kb
input:
40 1000
output:
617159088
result:
ok 1 number(s): "617159088"
Test #16:
score: 0
Accepted
time: 8ms
memory: 8016kb
input:
40 900
output:
729805907
result:
ok 1 number(s): "729805907"
Test #17:
score: 0
Accepted
time: 23ms
memory: 8192kb
input:
60 1830
output:
16340084
result:
ok 1 number(s): "16340084"
Test #18:
score: 0
Accepted
time: 24ms
memory: 8332kb
input:
60 2000
output:
832198921
result:
ok 1 number(s): "832198921"
Test #19:
score: 0
Accepted
time: 140ms
memory: 10024kb
input:
100 5050
output:
437918130
result:
ok 1 number(s): "437918130"
Test #20:
score: 0
Accepted
time: 23ms
memory: 8320kb
input:
100 700
output:
0
result:
ok 1 number(s): "0"
Test #21:
score: 0
Accepted
time: 268ms
memory: 11448kb
input:
100 10000
output:
0
result:
ok 1 number(s): "0"