BZOJ3308 九月的咖啡店

Orz PoPoQQQ

话说这题还有要注意的地方。。。

就是。。。不能加SLF优化，千万不能加

n = 40000，不加本机跑出来2sec，加了跑出来40sec。。。【给跪了

 /**************************************************************
     Problem: 3308
     User: rausen
     Language: C++
     Result: Accepted
     Time:27500 ms
     Memory:32752 kb
 ****************************************************************/

 #include <cstdio>
 #include <algorithm>
 #include <bitset>

 using namespace std;
 const int N = 2e4 + ;
 const int Cnt = N * ;
 const int M = Cnt * ;
 const int inf = 1e9;

 struct edges {
     int next, to, f, cost;
     edges() {}
     edges(int _n, int _t, int _f, int _c) : next(_n), to(_t), f(_f), cost(_c) {}
 } e[M];

 int n, ans, S, T;
 int first[N], tot = ;
 bitset <Cnt> not_p;
 int pr[N], tot_p, tot_a, tot_b;
 int d[N], g[N], v[N];

 inline void Add_Edges(int x, int y, int f, int c) {
     e[++tot] = edges(first[x], y, f, c), first[x] = tot;
     e[++tot] = edges(first[y], x, , -c), first[y] = tot;
 }

 inline void calc() {
     static int x;
     for (x = g[T]; x; x = g[e[x ^ ].to])
         --e[x].f, ++e[x ^ ].f;
 }

 #define y e[x].to
 inline bool spfa() {
     static int x, now, q[];
     static unsigned short l, r;
     for (x = ; x <= T; ++x)
         d[x] = -inf;
     d[S] = , v[S] = , q[] = S;
     for(l = r = ; l != r + ; ) {
         now = q[l++];
         for (x = first[now]; x; x = e[x].next) {
             if (e[x].f && d[now] + e[x].cost > d[y]) {
                 d[y] = d[now] + e[x].cost, g[y] = x;
                 if (!v[y])
                     v[y] = , q[++r] = y;
             }
         }
         v[now] = ;
     }
     return d[T] >= ;
 }
 #undef y

 inline int work() {
     int res = ;
     while (spfa())
         calc(), res += d[T];
     return res;
 }

 void get_prime(int N) {
     int i, j, k;
     for (i = ; i <= n; ++i) {
         if (!not_p[i]) pr[++tot_p] = i;
         for (j = ; j <= tot_p; ++j) {
             if ((k = i * pr[j]) > N) break;
             not_p[k] = ;
             if (i % pr[j] == ) break;
         }
     }
 }

 inline int get(int n, int p) {
     static int res;
     for (res = ; res * p <= n; res *= p);
     return res;
 }

 int main() {
     int i, j, tmp;
     scanf("%d", &n);
     get_prime(n);
     for (i = ; i <= tot_p && 1ll * pr[i] * pr[i] <= n; ++i) ++tot_a;
     for (; i <= tot_p && pr[i] *  <= n; ++i) ++tot_b;
     for (; i <= tot_p; ++i) ans += pr[i];
     S = tot_a + tot_b + , T = S + ;

 #define J j + tot_a
     for (i = ; i <= tot_a; ++i)
         Add_Edges(S, i, , ), Add_Edges(i, T, , get(n, pr[i]));
     for (j = ; j <= tot_b; ++j)
         Add_Edges(S, J, , pr[J]), Add_Edges(J, T, , );
     for (i = ; i <= tot_a; ++i)
         for (j = ; j <= tot_b; ++j)
             if ((tmp = get(n / pr[J], pr[i]) * pr[J]) > get(n, pr[i]) + pr[J])
                 Add_Edges(i, J, , tmp);
 #undef J
     printf("%d\n", ans +  + work());
     return ;
 }

(p.s. 成功成为最慢的2333)