//This is the main DLL file.

#include "stdafx.h"
#include "numerik.h"
#include "stdio.h"
#include "math.h"

double f(double x){
       return (exp(-x)-x);
}
void main() {
    double h[100],a,b,e,fa,fb,xr,fx;
    int n,i;

    printf("\t\t****************\n");
    printf("\t\t|Metode Biseksi|\n");
    printf("\t\t****************\n");
    printf("Input batas bawah(a)\t\t:");
    scanf_s("%lf",&a);
//masukkan nila a
    printf("Input batas atas(b)\t\t:");
    scanf_s("%lf",&b);
//masukkan nilai b
    printf("Input toleransi error\t\t:");
    scanf_s("%lf",&e);
//masukkan e
    printf("Input iterasi maksimum(N)\t:");
    scanf_s("%d",&n);
//masukkan N
    fa=f(a);
    fb=f(b);
    if(fa*fb>0)     //cek apakah (fa*fb>0)
        printf("tidak ditemukan akar\n");       //jika benar,maka print tdk ditemukan akar
    else{
            i=0;    //cek lagi, apakah I=0
            printf("----------------------------------------------------------------\n");
            printf("|%3s|%11s|%11s|%11s|%11s|%11s|\n","i","a","b","xr","f(a)","f(xr)");
            printf("----------------------------------------------------------------\n");
                    //cetak hasil
    while (i<=n)        //ketika i<n
        {
            xr=(a+b)/2;     //maka hitung nilai xr
            h[i]=f(xr);
            fx=f(xr);
printf("|%3d|%11lf|%11lf|%11lf|%11lf|%11lf|\n",i+1, a, b, xr,fa,f(xr)); //cetak hasil
    if(h[i]*fa<0){      //cek apakah (h[i]*fa<0)
            b=xr;//jika ya maka b=xr dan fb= f(xr)
            fb= f(xr);
          }
            else{ //jika tidak maka a=xr dan fa= f(xr)
                    a=xr;
                    fa= f(xr);
        }

        i++;
if (fabs(b-a)<=e || i>(n-1))    //cek apakah (fabs(b-a)<=e|| i>(n-1))&dimutlakkan
            break;              //jika yaa maka berhenti pada looping
    }
    printf("----------------------------------------------------------------\n");
    printf("Akar persamaan adalah %lf\n",xr);       //cetak akar
    if(f(xr)<0){        //cek apakah f(xr)<0
    fx=f(xr)*-1;        //jika yaa,hitung nilai fx
    printf("Nilai error = %lf\n",fx);               //cetak error
        }
    else        //jika tidak
    printf("Nilai error = %lf\n",fx);               //tetap cetak error
    }
}