Henrique Miranda

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

#define POINTS 1.8
#define DIM 100
#define MDIM 50

int main()
{
    //int dim = 1000, mdim = dim/2;
    float mat[DIM][DIM], vel, a;
    double num, den, delta = 1;
    int i = 0, h = 0, it = 0;
    //char string[6];
    //FILE *fp;

    //semente
    mat[MDIM][MDIM] = 0;

    //desenhar pontos
    for(a = .5;  a < POINTS; a+=.01)
    {

        //preencher a grelha com 1's nas fronteiras
        for(i = 0; i < DIM; i++)
        {
            mat[i][0] = 1;
            mat[0][i] = 1;
            mat[99][i] = 1;
            mat[i][99] = 1;
        }

        //preencher a grelha com .8 no resto do tabuleiro
        for(i = 1; i < (DIM - 1); i++)
        {
             for(h = 1; h < (DIM - 1); h++)
             {
                 mat[i][h] = .8;
             }
        }

        //processo
        while (delta > .005)
        {
            for(i = 0; i < DIM; i++)
            {
                for(h = 0; h < DIM; h++)
                {
                    if (mat[i][h] != 0 && mat[i][h] != 1)
                    {
                        vel = ((mat[i+1][h] + mat[i-1][h] + mat[i][h+1] + mat[i][h-1]) / 4) - mat[i][h];
                        mat[i][h] += a*vel;
                    }

                    den += (mat[i][h]) * (mat[i][h]);
                    num += vel*vel;
                }
            }

        it += 1;
        delta = sqrt (num / den);

        //imprimir para ficheiro
        /*sprintf(string, "file%d.dat", c);
        fp=fopen(string,"w");

        for(i = 0; i < DIM; i++)
        {
            for(h = 0; h < DIM; h++)
            {
                fprintf(fp,"%d %d %f\n", i, h, mat[i][h]);
            }
        }

        fclose(fp);*/

        }

        printf("%f %d\n", a, it);
        it = 0;
        delta = 1;

    }

    return 0;
}