POJ 2441 Arrange The Bulls (state compression dp+ scrolling array)

Test instructions

n Cattle and M-barn, each cow has its own favorite P-Barn (1<=p<=m), asking how many ways to arrange for the N-cow.

Analysis:

DP[I][J] Represents the number of methods of the I cow in J state.

DP[I][J] = Sigma (Dp[i-1][k]) (k from 0 to 1<<m).

To be optimized with a scrolling array, otherwise dp[20][1<<20] will mle!

Note the emptying of the scrolling array = =!

1#include <stdio.h>2#include <cstring>3#include <iostream>4#include <algorithm>5#include <cstdlib>6#include <cmath>7#include <vector>8#include <queue>9#include <map>Ten#include <Set> One  A using namespacestd; -  -typedefLong Longll; the  -vector<int> p[ -]; - intdp[2][1<< -],n; -  + intMain () - { +     intm,x,y; A      while(~SCANF ("%d%d",&n,&m)) at     { -          for(intI=1; i<=n;i++) -         { - p[i].clear (); -scanf"%d",&x); -              while(x--) in             { -scanf"%d",&y); to p[i].push_back (y); +             } -         } theMemset (DP,0,sizeof(DP)); *  $         intAll = (1&LT;&LT;M)-1;Panax Notoginsengdp[0][0] =1; -         intT; the  +          for(intI=1; i<=n;i++) A         { the              for(intk=0; k<=all;k++)//every state access once +             { -                 if(!dp[(i1) &1][K])Continue;//It is only when the K-state of the former I-1 cow has a value that it is possible to determine the method of the first cow $                  for(intj=0; J<p[i].size (); j + +) $                 { -t = p[i][j]-1; -                     if((k>>t) &1)Continue;//If there is a cow in the K state, it cannot be placed . thedp[i&1][k| (1&LT;&LT;T)] + = dp[(i-1) &1][k]; -                 }Wuyi             } thememset (dp[(i-1) &1],0,sizeof(Dp[(i1) &1]));//clear the next dimension to use for the scroll array -         } Wu  -         intAns =0; About          for(intI=1; i<=all;i++) $         { -ans+=dp[n&1][i]; -         } -printf"%d\n", ans); A     } +     return 0; the}

View Code

POJ 2441 Arrange The Bulls (state compression dp+ scrolling array)