[NOIP2010 提高组] 乌龟棋 - 洛谷

#include<bits/stdc++.h>
using namespace std;
const int N=41;
int f[N][N][N][N],num[351],g[5],n,m,x;
int main()
{scanf("%d %d",&n,&m);for(int i=1;i<=n;i++)scanf("%d",&num[i]);f[0][0][0][0]=num[1];for(int i=1;i<=m;i++){scanf("%d",&x);g[x]++;}for(int a=0;a<=g[1];a++){for(int b=0;b<=g[2];b++){for(int c=0;c<=g[3];c++){for(int d=0;d<=g[4];d++){int r=1+a+b*2+c*3+d*4;if(a!=0)	f[a][b][c][d]=max(f[a][b][c][d],f[a-1][b][c][d]+num[r]);if(b!=0)    f[a][b][c][d]=max(f[a][b][c][d],f[a][b-1][c][d]+num[r]);if(c!=0)    f[a][b][c][d]=max(f[a][b][c][d],f[a][b][c-1][d]+num[r]);if(d!=0)	f[a][b][c][d]=max(f[a][b][c][d],f[a][b][c][d-1]+num[r]);}}}}printf("%d\n",f[g[1]][g[2]][g[3]][g[4]]);
}