#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize ("Ofast")
typedef long long ll;
const int MOD = 1e9 + 7;
int add (int a, int b) {
a += b; if (a >= MOD) a -= MOD;
return a;
}
int sub (int a, int b) {
a -= b; if (a < 0) a += MOD;
return a;
}
int mul (int a, int b) {
return (a * 1ll * b) % MOD;
}
int power (int a, int b) {
if (!b) return 1;
int u = power(a, b >> 1);
u = mul(u, u);
if (b & 1) u = mul(u, a);
return u;
}
int n, l, a[101];
const int B = 1000;
int dp[102][102][2 * B + 1][3];
int ans (int x, int y, int z, int c) {
if (y < 1 || c < 0 || c > 2 || abs(z) > B) {
return 0;
}
if (x == n + 1) {
return y == 1 && z >= 0 && z <= l && c == 0;
}
int &ret = dp[x][y][z + B][c];
if (ret != -1) {
return ret;
}
if (y == 1) {
ret = 0;
ret = add(ret, mul(c, ans(x + 1, y, z, c)));
ret = add(ret, mul(c, ans(x + 1, y, z + a[x], c - 1)));
ret = add(ret, mul(c, ans(x + 1, y + 1, z - 2 * a[x], c)));
ret = add(ret, mul(c, ans(x + 1, y + 1, z - a[x], c - 1)));
return ret;
}
ret = 0;
ret = add(ret, mul(c, ans(x + 1, y + 1, z - 2 * a[x], c)));
ret = add(ret, mul(c, ans(x + 1, y + 1, z - a[x], c - 1)));
ret = add(ret, mul(c, ans(x + 1, y, z + a[x], c - 1)));
ret = add(ret, mul(y - 1, ans(x + 1, y + 1, z - 2 * a[x], c)));
ret = add(ret, mul(y - 1, ans(x + 1, y - 1, z + 2 * a[x], c)));
ret = add(ret, mul(2 * y - 2 + c, ans(x + 1, y, z, c)));
return ret;
}
void solve () {
memset(dp, -1, sizeof(dp));
cin >> n >> l;
for (int i = 1; i <= n; i++) {
cin >> a[i];
}
if (n == 1) {
cout << 1 << '\n';
return;
}
sort(a + 1, a + n + 1);
int sum = ans(2, 1, -a[1], 1);
sum = mul(sum, 2);
sum = add(sum, ans(2, 1, -2 * a[1], 2));
cout << sum << '\n';
}
signed main () {
ios::sync_with_stdio(0); cin.tie(0);
int tc = 1; //cin >> tc;
while (tc--) solve();
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
110 ms |
244888 KB |
Output is correct |
2 |
Correct |
105 ms |
244828 KB |
Output is correct |
3 |
Correct |
106 ms |
244816 KB |
Output is correct |
4 |
Correct |
107 ms |
244820 KB |
Output is correct |
5 |
Correct |
105 ms |
244784 KB |
Output is correct |
6 |
Correct |
106 ms |
244816 KB |
Output is correct |
7 |
Correct |
107 ms |
244676 KB |
Output is correct |
8 |
Correct |
110 ms |
244848 KB |
Output is correct |
9 |
Correct |
106 ms |
244820 KB |
Output is correct |
10 |
Correct |
108 ms |
244820 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
105 ms |
244820 KB |
Output is correct |
2 |
Correct |
109 ms |
244816 KB |
Output is correct |
3 |
Correct |
103 ms |
244820 KB |
Output is correct |
4 |
Correct |
120 ms |
244744 KB |
Output is correct |
5 |
Correct |
107 ms |
244744 KB |
Output is correct |
6 |
Correct |
109 ms |
244820 KB |
Output is correct |
7 |
Correct |
112 ms |
244820 KB |
Output is correct |
8 |
Correct |
108 ms |
244640 KB |
Output is correct |
9 |
Correct |
104 ms |
244820 KB |
Output is correct |
10 |
Correct |
118 ms |
244640 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
110 ms |
244888 KB |
Output is correct |
2 |
Correct |
105 ms |
244828 KB |
Output is correct |
3 |
Correct |
106 ms |
244816 KB |
Output is correct |
4 |
Correct |
107 ms |
244820 KB |
Output is correct |
5 |
Correct |
105 ms |
244784 KB |
Output is correct |
6 |
Correct |
106 ms |
244816 KB |
Output is correct |
7 |
Correct |
107 ms |
244676 KB |
Output is correct |
8 |
Correct |
110 ms |
244848 KB |
Output is correct |
9 |
Correct |
106 ms |
244820 KB |
Output is correct |
10 |
Correct |
108 ms |
244820 KB |
Output is correct |
11 |
Correct |
105 ms |
244820 KB |
Output is correct |
12 |
Correct |
109 ms |
244816 KB |
Output is correct |
13 |
Correct |
103 ms |
244820 KB |
Output is correct |
14 |
Correct |
120 ms |
244744 KB |
Output is correct |
15 |
Correct |
107 ms |
244744 KB |
Output is correct |
16 |
Correct |
109 ms |
244820 KB |
Output is correct |
17 |
Correct |
112 ms |
244820 KB |
Output is correct |
18 |
Correct |
108 ms |
244640 KB |
Output is correct |
19 |
Correct |
104 ms |
244820 KB |
Output is correct |
20 |
Correct |
118 ms |
244640 KB |
Output is correct |
21 |
Correct |
133 ms |
244816 KB |
Output is correct |
22 |
Incorrect |
296 ms |
244884 KB |
Output isn't correct |
23 |
Halted |
0 ms |
0 KB |
- |