zoukankan      html  css  js  c++  java
  • [HDOJ6149] Valley Numer II(枚举,状压DP)

    题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=6149

    比赛时这题想歪到最大流了,实际上高点至多只有15个。因此可以枚举低点,再枚举低点相连的高点做dp。

    f(i,j)代表前i个低点,此时高点使用状态为j时的最多三元组数。事先预处理每一个高点在bit位中的位置,dp的时候直接枚举任意两个不等的高点,此时状态st,再枚举所有状态,把j^st的状态更新到j上就行,因为低点可能有间隔,所以用滚动数组即可。

      1 /*
      2 ━━━━━┒ギリギリ♂ eye!
      3 ┓┏┓┏┓┃キリキリ♂ mind!
      4 ┛┗┛┗┛┃\○/
      5 ┓┏┓┏┓┃ /
      6 ┛┗┛┗┛┃ノ)
      7 ┓┏┓┏┓┃
      8 ┛┗┛┗┛┃
      9 ┓┏┓┏┓┃
     10 ┛┗┛┗┛┃
     11 ┓┏┓┏┓┃
     12 ┛┗┛┗┛┃
     13 ┓┏┓┏┓┃
     14 ┃┃┃┃┃┃
     15 ┻┻┻┻┻┻
     16 */
     17 #include <algorithm>
     18 #include <iostream>
     19 #include <iomanip>
     20 #include <cstring>
     21 #include <climits>
     22 #include <complex>
     23 #include <cassert>
     24 #include <cstdio>
     25 #include <bitset>
     26 #include <vector>
     27 #include <deque>
     28 #include <queue>
     29 #include <stack>
     30 #include <ctime>
     31 #include <set>
     32 #include <map>
     33 #include <cmath>
     34 using namespace std;
     35 #define fr first
     36 #define sc second
     37 #define cl clear
     38 #define BUG puts("here!!!")
     39 #define W(a) while(a--)
     40 #define pb(a) push_back(a)
     41 #define Rint(a) scanf("%d", &a)
     42 #define Rll(a) scanf("%lld", &a)
     43 #define Rs(a) scanf("%s", a)
     44 #define Cin(a) cin >> a
     45 #define FRead() freopen("in", "r", stdin)
     46 #define FWrite() freopen("out", "w", stdout)
     47 #define Rep(i, len) for(int i = 0; i < (len); i++)
     48 #define For(i, a, len) for(int i = (a); i < (len); i++)
     49 #define Cls(a) memset((a), 0, sizeof(a))
     50 #define Clr(a, x) memset((a), (x), sizeof(a))
     51 #define Full(a) memset((a), 0x7f7f7f, sizeof(a))
     52 #define lrt rt << 1
     53 #define rrt rt << 1 | 1
     54 #define pi 3.14159265359
     55 #define RT return
     56 #define lowbit(x) x & (-x)
     57 #define onenum(x) __builtin_popcount(x)
     58 typedef long long LL;
     59 typedef long double LD;
     60 typedef unsigned long long ULL;
     61 typedef pair<int, int> pii;
     62 typedef pair<string, int> psi;
     63 typedef pair<LL, LL> pll;
     64 typedef map<string, int> msi;
     65 typedef vector<int> vi;
     66 typedef vector<LL> vl;
     67 typedef vector<vl> vvl;
     68 typedef vector<bool> vb;
     69 
     70 const int maxn = 33;
     71 const int maxm = 1 << 16;
     72 int n, m, k, f[2][maxm];
     73 int mask[maxn];
     74 vi G[maxn];
     75 
     76 signed main() {
     77     // FRead();
     78     int T, u, v;
     79     Rint(T);
     80     W(T) {
     81         Clr(mask, -1); Cls(f);
     82         Rint(n); Rint(m); Rint(k);
     83         Rep(i, n) G[i].clear();
     84         Rep(i, m) {
     85             Rint(u); Rint(v); u--, v--;
     86             G[u].pb(v); G[v].pb(u);
     87         }
     88         Rep(i, k) Rint(u), mask[--u] = i;
     89         int kk = 1 << k;
     90         Rep(i, n) {
     91             if(mask[i] != -1) continue;
     92             Rep(j, kk) f[1][j] = f[0][j];
     93             for(auto u : G[i]) {
     94                 for(auto v : G[i]) {
     95                     if(u == v) continue;
     96                     if(mask[u] == -1 || mask[v] == -1) continue;
     97                     int st = (1 << mask[u]) | (1 << mask[v]);
     98                     Rep(j, kk) {
     99                         if((j & st) == st) {
    100                             f[0][j] = max(f[0][j], f[1][j^st]+1);
    101                         }
    102                     }
    103                 }
    104             }
    105         }
    106         printf("%d
    ", f[0][kk-1]);
    107     }
    108     RT 0;
    109 }
  • 相关阅读:
    获取请求IP
    Excel导入工具类兼容xls和xlsx
    Openshift 4.3环境的离线Operatorhub安装
    RHEL学习
    OpenShift Service Mesh 培训作业
    OpenId Connect认证配置
    Route Sharding in OpenShift 4.3
    OpenShift 4.3环境中创建基于Go的Operator
    Quay和Clair的集成
    Quay 基础版安装和部署
  • 原文地址:https://www.cnblogs.com/kirai/p/7395817.html
Copyright © 2011-2022 走看看