bisection.c

#include <stdio.h>
#include <math.h>
#define ex 0.01

double foo(double x){
    return pow(x,3) - x - 4;
}
 
double bisection(){
    int n = 1, i;
    double a = 0.0;
    while(foo(a)*foo(a+1) > 0)
        a++;
    double b = a+1, x0;
    printf("%cn\t%ca\t%cb\t%cf(a)\t%cf(b)\t%cx0\t%cf(x0)\t%c(b-a)\t%c\n", 179, 179, 179, 179, 179, 179, 179, 179, 179, 179);
    
    printf("%c",195);
    for(i=0; i<63; i++)
    	printf("%c", 196);
    printf("%c",180);
    printf("\n");
    
    do{
        x0 = (a+b)/2;
        printf("%c%d\t%c%.2lf\t%c%.2lf\t%c%.2lf\t%c%.2lf\t%c%.2lf\t%c%.2lf\t%c%.2lf\t%c\n", 179, n++, 179, a, 179, b, 179, foo(a), 179, foo(b), 179, x0, 179, foo(x0), 179, (b-a), 179);
        
        
        if(foo(x0)>0)
            b = x0;
        else if(foo(x0)<0)
            a = x0;
        else
            return x0;
    }while((b-a)>ex);
   
    return x0;
}

int main(void) {
	double b = bisection();

	int i;
	printf("%c",192);
    for(i=0; i<63; i++)
    	printf("%c", 196);
    printf("%c",217);
    
    printf("\n\nThe root is: %g", b);
    return 0;
}