• UVA12298 Super Poker II 题解


    Description

    Luogu传送门

    Solution

    其实就是个 NTT 多项式乘法板子。

    我不会告诉你我一开始还推了半天生成函数(然后发现直接把 5e4 的系数全都直接赋值就完了QwQ

    那么本题的解法就是这样=-=

    开 4 个数组,表示 4 种花色的多项式。对于每一组数据,暴力把每一位的系数都赋上:

    合数位系数都为 1,质数位都为 0,再把被删掉牌的位系数改为 0。

    注意:不知道为什么在本题中 1 被看成了质数,系数为 0。

    然后把 4 个数组都卷起来就完了。

    然后就没啦。

    还有一个小问题,一般的模数会被卡,我是直接用的 kls 的模数,得用 __int128

    Code

    #include <bits/stdc++.h>
    #define Int __int128
    
    using namespace std;
    
    namespace IO{
        inline Int read(char &ch){
            Int x = 0;
            ch = getchar();
            while(!isdigit(ch)) ch = getchar();
            while(isdigit(ch)) x = (x << 3) + (x << 1) + ch - '0', ch = getchar();
            return x;
        }
    
        template <typename T> inline void write(T x){
            if(x > 9) write(x / 10);
            putchar(x % 10 + '0');
        }
    }
    using namespace IO;
    
    const Int N = 1e6 + 10;
    const Int P = 5e4;
    const Int mod = 4179340454199820289ll;
    const Int G = 3, Gi = 1393113484733273430ll;
    Int n, m, k;
    Int a[N], b[N], c[N], d[N], e[N], rev[N];
    Int p[N], tot;
    bool vis[N];
    char ch;
    
    namespace NTT{
        Int lim, len;
    
        inline Int qpow(Int a, Int b){
            Int res = 1;
            while(b){
                if(b & 1) res = res * a % mod;
                a = a * a % mod, b >>= 1;
            }
            return res;
        }
    
        inline void get_rev(Int n){
            lim = 1, len = 0;
            while(lim <= n) lim <<= 1, ++len;
            for(int i = 0; i <= lim; ++i) p[i] = (p[i >> 1] >> 1) | ((i & 1) << (len - 1));
        }
    
        inline void ntt(Int A[], Int lim, Int type){
            for(int i = 0; i < lim; ++i)
                if(i < p[i]) swap(A[i], A[p[i]]);
            for(int mid = 1; mid < lim; mid <<= 1){
                Int Wn = qpow(type == 1 ? G : Gi, (mod - 1) / (mid << 1));
                for(int i = 0; i < lim; i += (mid << 1)){
                    Int w = 1;
                    for(int j = 0; j < mid; ++j, w = w * Wn % mod){
                        Int x = A[i + j], y = w * A[i + j + mid] % mod;
                        A[i + j] = (x + y) % mod;
                        A[i + j + mid] = (x - y + mod) % mod;
                    }
                }
            }
            if(type == 1) return;
            Int inv = qpow(lim, mod - 2);
            for(int i = 0; i < lim; ++i) A[i] = A[i] * inv % mod;
        }
    
        inline void Mul(Int n, Int m, Int a[], Int b[]){
            get_rev(n + m);
            ntt(a, lim, 1), ntt(b, lim, 1);
            for(int i = 0; i <= lim; ++i) a[i] = a[i] * b[i] % mod;
            ntt(a, lim, -1);
        }
    }
    using namespace NTT;
    
    inline void euler(){
        for(int i = 2; i <= P; ++i){
            if(!vis[i]) p[++tot] = i;
            for(int j = 1; j <= tot && i * p[j] <= P; ++j){
                vis[i * p[j]] = 1;
                if(i % p[j] == 0) break;
            }
        }
    }
    
    inline void del(){
        int x = read(ch);
        if(ch == 'S') a[x] = 0;
        if(ch == 'H') b[x] = 0;
        if(ch == 'C') c[x] = 0;
        if(ch == 'D') d[x] = 0;
    }
    
    signed main(){
        euler();
        while(1){
            n = read(ch), m = read(ch), k = read(ch);
            if(!n && !m && !k) break;
            memset(a, 0, sizeof(a)), memset(b, 0, sizeof(b));
            memset(c, 0, sizeof(c)), memset(d, 0, sizeof(d));
            for(int i = 0; i <= m; ++i)
                a[i] = b[i] = c[i] = d[i] = vis[i];
            for(int i = 1; i <= k; ++i) del();
            Mul(m, m, a, b), Mul(m, m, c, d), Mul(m << 1, m << 1, a, c);
            for(int i = n; i <= m; ++i) write(a[i]), puts("");
            puts("");
        }
        return 0;
    }
    

    \[\_EOF\_ \]

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  • 原文地址:https://www.cnblogs.com/xixike/p/15634836.html
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