mirror of
https://git.sb/baoshuo/OI-codes.git
synced 2024-12-11 17:46:26 +00:00
76 lines
1.4 KiB
C++
76 lines
1.4 KiB
C++
|
#include <iostream>
|
||
|
|
||
|
using std::cin;
|
||
|
using std::cout;
|
||
|
const char endl = '\n';
|
||
|
|
||
|
const int N = 2e5 + 5,
|
||
|
K = 55;
|
||
|
const int mod = 1e9 + 7;
|
||
|
|
||
|
int m, k, d, cnt;
|
||
|
long long f[K][K], p[N][K], s[N][K], sum;
|
||
|
|
||
|
long long binpow(long long a, long long b) {
|
||
|
a %= mod;
|
||
|
|
||
|
long long res = 1;
|
||
|
|
||
|
while (b) {
|
||
|
if (b & 1) res = res * a % mod;
|
||
|
a = a * a % mod;
|
||
|
b >>= 1;
|
||
|
}
|
||
|
|
||
|
return res;
|
||
|
}
|
||
|
|
||
|
int main() {
|
||
|
std::ios::sync_with_stdio(false);
|
||
|
cin.tie(nullptr);
|
||
|
|
||
|
cin >> m >> k;
|
||
|
|
||
|
f[0][0] = 1;
|
||
|
for (int i = 1; i <= k; i++) {
|
||
|
f[i][0] = 1;
|
||
|
|
||
|
for (int j = 1; j <= i; j++) {
|
||
|
f[i][j] = (f[i - 1][j - 1] + f[i - 1][j]) % mod;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
while (m--) {
|
||
|
int op;
|
||
|
|
||
|
cin >> op;
|
||
|
|
||
|
if (op == 0) {
|
||
|
int x;
|
||
|
|
||
|
cin >> x;
|
||
|
|
||
|
p[++cnt][0] = 1;
|
||
|
s[cnt][0] = (s[cnt - 1][0] + p[cnt][0]) % mod;
|
||
|
|
||
|
for (int i = 1; i <= k; i++) {
|
||
|
p[cnt][i] = (p[cnt][i - 1] * (x - d) % mod + mod) % mod;
|
||
|
s[cnt][i] = (s[cnt - 1][i] + p[cnt][i]) % mod;
|
||
|
}
|
||
|
|
||
|
sum = (sum + binpow(x, k)) % mod;
|
||
|
} else { // op == 1
|
||
|
d++;
|
||
|
|
||
|
sum = 0;
|
||
|
for (int i = 0; i <= k; i++) {
|
||
|
sum = (sum + f[k][i] * binpow(d, i) % mod * s[cnt][k - i] % mod) % mod;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
cout << sum << endl;
|
||
|
}
|
||
|
|
||
|
return 0;
|
||
|
}
|