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


void initFiles( char inputFile[], char outputFile[] )
{
    printf( "Algandmete faili nimi on: " );
    scanf( "%s", inputFile );

    printf( "Tulemuste faili nimi on: " );
    scanf( "%s", outputFile );
}

void otvet(double X, double Y)
{

     Y = log( sqrt( exp( (double)(X - 1) ) ) );

        if( exp( X - 1 ) < 0 ) {
            printf("Puudub\n");
        } else {
            printf("%10.4lf  |%10.4lf\n", X, Y);
            //fprintf(fo,"%10.4lf  |%10.4lf\n", X, Y);
        }
     }


int main( int argc, char **argv )
{

  char inputFile[10], outputFile[10];
  double A, B, H, X, Y;
  int i = 0;
  int x;
  int digits[2];
  char letter[3] = {'A', 'B'};

  FILE *fi, *fo;

  initFiles( inputFile, outputFile );

    fi = fopen( inputFile, "r" );       //fail avatakse lugemiseks
    fo = fopen( outputFile, "w" );


    if ( NULL == fi )
    {
        printf( "%s fail polnud voimalik avada.\n", inputFile );
        fprintf(fo, "%s fail polnud voimalik avada.\n", inputFile );

        return 1;
    }

    if ( NULL == fo )
    {
        printf( "%s fail polnud voimalik avada.\n", outputFile );

        return 1;
    }

    while ( EOF != fscanf( fi, "%d", &x ) )     //loeb failist lopuni
    {
        if ( 2 > i )
        {
            fprintf( fo, "%c = %d\n", letter[ i ], x );
            digits[ i ] = x;
        }
        i++;

    }


    A = digits[0];
    B = digits[1];


     if( A > B ) {
        do {
            printf("H (H < 0) = ");
            scanf("%lf", &H);
            fprintf(fo, "H (H < 0) = ", H);

        } while ( H >= 0 );
    } else {
        do {
            printf("H (H > 0) = ");
            scanf("%lf", &H);
            fprintf(fo, "H (H < 0) = ", H);

        } while ( H <= 0 );
    }


    fprintf(fo,"\n");

    printf("  ARGUMENT  |  Funktsioon\n");
    fprintf(fo, "  ARGUMENT  |  Funktsioon\n");
    printf("____________|_____________\n");
    fprintf(fo, "____________|_____________\n");

   i=0;

    do {

        if( i == 0 ) {
            X = A;
        }

        if( X > B ) {
            if ( i == 1 ) {
               X = A + H;
            }
            if( i > 1 ) {
                X = A + i * H;
            }
            if(X<B) {
                     return 0;
                     }
        }

        if( X < B ) {
            if( i == 1 ) {
                X = A + H;
            }
            if( i > 1 ) {
                X = A + i * H;
            }
            if(X>B) {
                     return 0;
                     }
        }

        otvet( X, Y);
        fprintf(fo,"%10.4lf  |%10.4lf\n", X, Y);

       /* Y = log( sqrt( exp( (double)(X - 1) ) ) );

        if( exp( X - 1 ) < 0 ) {
            printf("Puudub\n");
            fprintf(fo, "Puudub\n");
        } else {
            printf("%10.4lf  |%10.4lf\n", X, Y);
            fprintf(fo,"%10.4lf  |%10.4lf\n", X, Y);
        }  */

        if( X == B ) {
            return 0;
        }


        i++;

    } while(1);

    return 0;
}