Recursive, memory Search, (checkerboard segmentation)

Topic Link http://poj.org/problem?id=1191

problem: 1191User: yinjianMemory: 568K time: 16MSLanguage: C + + Result: Accepted

Problem Solving Report:

1, the formula can be used to simplify the mathematical method, is to find the number (sum) of the sum of the squares and the smallest.

2, each division has four kinds of cases (recursion).

3, each time the location of the division to be compared, so as to find the best.

#include <stdio.h>#include<math.h>#include<algorithm>#include<string.h>using namespacestd;ints[9][9];//the score of each latticeintsum[9][9];//(i,j) to a rectangular fraction of (intres[ the][9][9][9][9];//Fun 's record sheetintCalsum (intX1,intY1,intX2,inty2)//(X1,y1) to (x2,y2) the rectangle fraction and{    returnSum[x2][y2]-sum[x2][y1-1]-sum[x1-1][y2]+sum[x1-1][y1-1];}intFunintNintX1,intY1,intX2,inty2)//with (X1,Y1) as the upper-left corner, (x2,y2) is the bottom right corner of the rectangular checkerboard divided into n minutes after the smallest sum{    intt,a,b,c,e; intmin=0x3f3f3f3f; if(res[n][x1][y1][x2][y2]!=-1)        returnRes[n][x1][y1][x2][y2]; if(n==1) {T=calsum (X1,Y1,X2,Y2); Res[n][x1][y1][x2][y2]=t*T; returnt*T; }     for(a=x1;a<x2;a++) {C=calsum (A +1, y1,x2,y2);//The and of the Matrix on the rightE=calsum (X1,Y1,A,Y2);//The and of the left MatrixT=min (N-1, X1,y1,a,y2) +c*c,fun (n1, A +1, Y1,x2,y2) +e*e); if(min>t) min=T; }     for(b=y1;b<y2;b++) {C=calsum (x1,b+1, x2,y2);//The following matrix and theE=calsum (X1,Y1,X2,B);//The and of the matrix aboveT=min (N-1, x1,y1,x2,b) +c*c,fun (n1, x1,b+1, X2,y2) +e*e); if(min>t) min=T; } Res[n][x1][y1][x2][y2]=MIN; returnMIN;}intMain () {memset (sum,0,sizeof(sum)); memset (Res,-1,sizeof(res)); intN; scanf ("%d",&N);  for(intI=1;i<9; i++)    {         for(intj=1, rowsum=0;j<9; j + +) {scanf ("%d",&S[i][j]); Rowsum=rowsum+S[i][j]; SUM[I][J]=sum[i-1][j]+rowsum; }    }    DoubleResult=n*fun (N,1,1,8,8)-sum[8][8]*sum[8][8]; printf ("%.3f\n", sqrt (result/(nn))) ; return 0;}

Recursive, memory Search, (checkerboard segmentation)