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]/n));    return 0;}