#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 42;
ll n, k, h[N], g[N];
map<ll, ll> lft[N], rght[N], tmp;
int main(){
cin >> n >> k;
for (int i = 1; i <= n; i ++)
cin >> h[i] >> g[i];
lft[0][0] = 1;
for (int i = 1; i <= n / 2; i ++){
tmp.clear();
for (int j = 0; j < i; j ++){
if (h[j] > h[i]) continue;
for (auto [x, c] : lft[j]){
tmp[x + g[i]] += c;
}
}
lft[i] = tmp;
}
h[n + 1] = 1e9 + 7;
rght[n + 1][0] = 1;
for (int i = n; i > n / 2; i --){
tmp.clear();
for (int j = i + 1; j <= n + 1; j ++){
if (h[i] > h[j]) continue;
for (auto [x, c] : rght[j]){
tmp[x + g[i]] += c;
}
}
rght[i] = tmp;
}
ll ans = 0;
for (int i = 0; i <= n / 2; i ++){
for (int j = n / 2 + 1; j <= n + 1; j ++){
if (h[i] > h[j]) continue;
// cout << endl;
// cout << i << " -- " << j << " : " << endl;
auto p1 = lft[i].end();
auto p2 = rght[j].begin();
ll total = 0;
for (auto [x, c] : rght[j])
total += c;
while (p1 != lft[i].begin() and p2 != rght[j].end()){
p1--;
while (p2 != rght[j].end() and (p1 -> first) + (p2 -> first) < k){
total -= p2 -> second;
p2++;
}
if (p2 == rght[j].end()) break;
// cout << p1 -> first << " " << p1 -> second << " -- " << total << endl;
ans += p1 -> second * total;
}
}
}
cout << ans << endl;
}
/*
6 1
1 1
2 1
3 1
4 1
5 1
6 1
7 1
8 1
9 1
10 1
11 1
12 1
13 1
14 1
15 1
16 1
17 1
18 1
19 1
20 1
21 1
22 1
23 1
24 1
25 1
26 1
27 1
28 1
29 1
30 1
31 1
32 1
33 1
34 1
35 1
36 1
37 1
38 1
39 1
40 1
*/
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
440 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
33 ms |
8536 KB |
Output is correct |
2 |
Correct |
2 ms |
856 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
61 ms |
15700 KB |
Output is correct |
2 |
Correct |
11 ms |
2136 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
151 ms |
65536 KB |
Execution killed with signal 9 |
2 |
Halted |
0 ms |
0 KB |
- |