POJ1191-裸动态规划

#include <cstdio>
#include <iostream>
#include <cmath>
using namespace std;

const double INF=1000000000000.0;

int n;
double _x,w;
double s[9][9];
double f[9][9][9][9][16];

int main()
{
    scanf("%d",&n);
    for (int i=0; i<=8; i++) s[i][0]=s[0][i]=0;
    for (int i=1; i<=8; i++)
      for (int j=1; j<=8; j++)
      {
          scanf("%lf",&w);
          s[i][j]=s[i-1][j]+s[i][j-1]-s[i-1][j-1]+w;
      }
    _x=s[8][8]/n;
    for (int x1=1; x1<=8; x1++)
      for (int y1=1; y1<=8; y1++)
        for (int x2=x1; x2<=8; x2++)
          for (int y2=y1; y2<=8; y2++)
          {
              w=s[x2][y2]-s[x1-1][y2]-s[x2][y1-1]+s[x1-1][y1-1]-_x;
              f[x1][y1][x2][y2][1]=w*w;
              for (int i=2; i<=n; i++) f[x1][y1][x2][y2][i]=INF;
          }

    for (int i=2; i<=n; i++)
      for (int x1=1; x1<=8; x1++)
        for (int y1=1; y1<=8; y1++)
          for (int x2=x1; x2<=8; x2++)
            for (int y2=y1; y2<=8; y2++)
            {
                for (int k=x1; k<x2; k++)
                {
                  if (f[x1][y1][x2][y2][i]>f[x1][y1][k][y2][i-1]+f[k+1][y1][x2][y2][1])
                      f[x1][y1][x2][y2][i]=f[x1][y1][k][y2][i-1]+f[k+1][y1][x2][y2][1];
                  if (f[x1][y1][x2][y2][i]>f[x1][y1][k][y2][1]+f[k+1][y1][x2][y2][i-1])
                      f[x1][y1][x2][y2][i]=f[x1][y1][k][y2][1]+f[k+1][y1][x2][y2][i-1];
                }
                for (int k=y1; k<y2; k++)
                {
                  if (f[x1][y1][x2][y2][i]>f[x1][y1][x2][k][i-1]+f[x1][k+1][x2][y2][1])
                      f[x1][y1][x2][y2][i]=f[x1][y1][x2][k][i-1]+f[x1][k+1][x2][y2][1];
                  if (f[x1][y1][x2][y2][i]>f[x1][y1][x2][k][1]+f[x1][k+1][x2][y2][i-1])
                      f[x1][y1][x2][y2][i]=f[x1][y1][x2][k][1]+f[x1][k+1][x2][y2][i-1];
                }
            }
    printf("%.3f\n",sqrt(f[1][1][8][8]
/n));
    return 0;
}