比赛 |
2024年6月13日练习赛 |
评测结果 |
AAAAAAAAAAAAAAAAAAAA |
题目名称 |
组合数问题 |
最终得分 |
100 |
用户昵称 |
┭┮﹏┭┮ |
运行时间 |
0.301 s |
代码语言 |
C++ |
内存使用 |
0.00 MiB |
提交时间 |
2024-06-13 19:44:57 |
显示代码纯文本
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define in inline
#define re register
#define pii pair<int,int>
#define fi first
#define se second
#define pb(x) push_back(x)
#define D(i,a,b) for(re long double i = a;i >= b;i--)
#define F(i,a,b) for(re long long i = a;i <= b;i++)
const int N = 1e5+10;
const ll inf = 1e17;
ll read(){
ll x = 0,f = 1;char c = getchar();
for(;c < '0' || c > '9';c = getchar())if(c == '-')f = -1;
for(;c >= '0' && c <= '9';c = getchar())x = (x<<1) + (x<<3) + c-'0';
return x * f;
}
ll n,p,k,r;
struct Matrix{
ll a[60][60],n,m;
void clear(){memset(a,0,sizeof a),n = m = 0;}
Matrix operator * (const Matrix &x)const{
Matrix y;y.clear();
y.n = n,y.m = m;
for(int i = 0;i < n;i++){
for(int j = 0;j < m;j++){
for(int k = 0;k < m;k++)y.a[i][j] = (y.a[i][j] + a[i][k] * x.a[k][j] % p) % p;
}
}
return y;
}
}U,F;
int main(){
freopen("problem_heoi2017.in","r",stdin);
freopen("problem_heoi2017.out","w",stdout);
n = read(),p = read(),k = read(),r = read();
U.n = 1,U.m = k;
if(k == 1)U.a[0][0] = 2 % p;
else U.a[0][0] = U.a[0][1] = 1;//初始化
F.n = F.m = k;
F(i,0,k-1){
F.a[(i-1+k)%k][i] += 1;
F.a[i][i] += 1;
}
n = n * k - 1;
while(n){
if(n & 1)U = U * F;
F = F * F;
n >>= 1;
}//矩阵快速幂
printf("%lld\n",U.a[0][r]);
return cerr << "Time : " << clock() << " ms" << endl, 0;
}