laplace

#include<stdio.h>
#include<math.h>

int main()
{ 
  
  double B,L,T,R;
  double u[15][15][10000];
  int i,j,k;


  FILE *fp;
  fp=fopen("cfd result.txt","w");
   
 
  
  
  printf("Enter the top bottom left and right Boundary value");
  scanf("%lf %lf %lf %lf",&T,&B,&L,&R);
  


 for(i=0;i<15;i++)
  for(j=0;j<15;j++)
    u[i][j][0]=0;
  


  
for(k=1;k<1000;k++) 
  for(j=0;j<15;j++)
    for(i=0;i<15;i++)
        { if(i==0&&j==0)
          u[i][j][k]=(u[i+1][j][k-1]+u[i][j+1][k-1]+2*B+2*L)/6;
         else if(i==0&&j==14)
          u[i][j][k]=(u[i+1][j][k-1]+u[i][j-1][k-1]+2*T+2*L)/6;
         else if(i==14&&j==14)
          u[i][j][k]=(u[i-1][j][k-1]+u[i][j-1][k-1]+2*T+2*R)/6;
         else if(i==14&&j==0)
          u[i][j][k]=(u[i-1][j][k-1]+u[i][j+1][k-1]+2*R+2*B)/6;
         else if(i==0)
          u[i][j][k]=(u[i+1][j][k-1]+u[i][j+1][k-1]+u[i][j-1][k-1]+2*L)/5;
         else if(i==14)
          u[i][j][k]=(u[i-1][j][k-1]+u[i][j+1][k-1]+u[i][j-1][k-1]+2*R)/5;
         else if(j==0)
          u[i][j][k]=(u[i+1][j][k-1]+u[i][j+1][k-1]+u[i-1][j][k-1]+2*B)/5;
         else if(j==14)
          u[i][j][k]=(u[i+1][j][k-1]+u[i-1][j][k-1]+u[i][j-1][k-1]+2*T)/5;
         else
          u[i][j][k]=(u[i+1][j][k-1]+u[i][j+1][k-1]+u[i][j-1][k-1]+u[i-1][j][k-1])/4;
         }


for(j=0;j<15;j++)
  { for(i=0;i<15;i++)
   {
     fprintf(fp,"%lf  ",u[i][j][k-1]);
   }
    fprintf(fp,"\n");
  }
return 0; 
}