【动态规划】bzoj1663 [Usaco2006 Open]赶集

http://blog.csdn.net/u011265346/article/details/44906469

#include<cstdio>
#include<algorithm>
using namespace std;
#define N 401
struct Point{int p,v;}a[N];
bool operator < (const Point &a,const Point &b){return a.v<b.v;}
int n,map[N][N],f[N];
int main()
{
//  freopen("bzoj1663.in","r",stdin);
    scanf("%d",&n);
    for(int i=1;i<=n;++i)
      {
        scanf("%d",&a[i].v);
        a[i].p=i;
      }
    sort(a+1,a+n+1);
    for(int i=1;i<=n;++i)
      for(int j=1;j<=n;++j)
        scanf("%d",&map[i][j]);
    for(int i=1;i<=n;++i)
      if(map[1][a[i].p]<=a[i].v)
        f[i]=1;
    for(int i=1;i<=n;++i)
      for(int j=1;j<i;++j)
        if(a[j].v+map[a[j].p][a[i].p]<=a[i].v)
          f[i]=max(f[i],f[j]+1);
    printf("%d\n",*max_element(f+1,f+1+n));
    return 0;
}