C11CAL - Tính toán
Tác giả: ladpro98
Ngôn ngữ: C++
#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <climits>
#include <cstdlib>
#include <ctime>
#include <memory.h>
#include <cassert>
#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define REP(i, a, b) for(int i = (a); i <=(b); i++)
#define FORD(i, a, b) for(int i = (a); i > (b); i--)
#define REPD(i, a, b) for(int i = (a); i >=(b); i--)
#define SZ(a) (int((a).size()))
#define ALL(a) (a).begin(), (a).end()
#define PB push_back
#define MP make_pair
#define LL long long
#define LD long double
#define II pair<int, int>
#define X first
#define Y second
#define VI vector<int>
const int D = 53;
const int MOD = 1000000007;
using namespace std;
int n, k, dim;
struct mat {LL a[D][D];};
mat base;
mat operator * (mat a, mat b) {
mat c;
FOR(i, 0, dim) FOR(j, 0, dim) {
c.a[i][j] = 0;
FOR(k, 0, dim)
c.a[i][j] = (c.a[i][j] + a.a[i][k] * b.a[k][j]) % MOD;
}
return c;
}
void setDim() {
memset(base.a, 0, sizeof base.a);
dim = k + 2;
base.a[0][0] = base.a[0][k + 1] = 1;
REP(i, 1, k + 1) {
base.a[i][1] = base.a[i][i] = 1;
FOR(j, 2, i)
base.a[i][j] = (base.a[i - 1][j] + base.a[i - 1][j - 1]) % MOD;
}
}
int main() {
ios :: sync_with_stdio(0); cin.tie(0);
while (cin >> n >> k) {
setDim();
mat a = base;
VI bin;
while (n) {
bin.PB(n & 1);
n >>= 1;
}
REPD(i, SZ(bin) - 2, 0) {
a = a * a;
if (bin[i]) a = a * base;
}
int ans = 0;
REP(i, 1, k + 1) ans = (ans + a.a[0][i]) % MOD;
cout << ans << '\n';
}
return 0;
}