"Bzoj" "1013" "JSOI2008" spherical space generator sphere

Gaussian elimination element

Gaussian elimination template problem

To tell you the truth, how did that equation Group (augmented matrix) come out? I haven't quite figured it out yet ...

1 /**************************************************************2 problem:10133 User:tunix4 language:c++5 result:accepted6 time:0 Ms7 memory:1272 KB8 ****************************************************************/9  Ten //Bzoj 1013 One#include <cmath> A#include <cstdio> -#include <cstring> -#include <cstdlib> the#include <iostream> -#include <algorithm> - #defineRep (i,n) for (int i=0;i<n;++i) - #defineF (i,j,n) for (int i=j;i<=n;++i) + #defineD (i,j,n) for (int i=j;i>=n;--i) - using namespacestd; + voidReadint&v) { Av=0;intsign=1;CharCh=GetChar (); at      while(ch<'0'|| Ch>'9'){if(ch=='-') sign=-1; Ch=GetChar ();} -      while(ch>='0'&&ch<='9') {v=v*Ten+ch-'0'; Ch=GetChar ();} -v*=Sign ; - } - /******************tamplate*********************/ - Const intn= One; intypedefDoubleMatrix[n][n]; - voidGauss (Matrix A,intN) { to     intI,j,k,r; +      for(i=0; i<n;++i) { -         //Select Line R and Exchange with line I theR=i; *          for(j=i+1; j<n;++j) $             if(Fabs (A[j][i]) > Fabs (a[r][i]) r=J;Panax Notoginseng         if(r!=i) for(j=0; j<=n;++j) Swap (A[r][j],a[i][j]); -           the         //The elimination of the I+1~n line with section +          for(k=i+1; k<n;++k) { A             DoubleF=a[k][i]/a[i][i];//in order to make a[k][i]=0, the multiples of line I multiply the              for(J=I;J&LT;=N;++J) a[k][j]-=f*A[i][j]; +         } -     } $     //The process of generation back $      for(i=n-1; i>=0; i--){ -          for(j=i+1; j<n;j++) -a[i][n]-=a[j][n]*A[i][j]; theA[i][n]/=A[i][i]; -     }Wuyi } the Matrix F; - intN; Wu intMain () { -scanf"%d",&n); AboutF (I,0, N) { $ Rep (j,n) { -scanf"%LF",&f[i][j]); -f[i][n]-=f[i][j]*F[i][j]; -f[i][j]*=-2.0; A             if(i) f[i-1][j]-=F[i][j]; +         } the         if(i) f[i-1][n]-=F[i][n]; -     } $ Gauss (f,n); theprintf"%.3f", f[0][n]); the      for(intI=1; i<n;++i) printf ("%.3f", F[i][n]); the     return 0; the}

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"Bzoj" "1013" "JSOI2008" spherical space generator sphere