Bisection Method

//Bisection Method

#include<stdio.h>
#include<math.h>
float root( float x)
{
  float f;
  f=x*x*x-x-1;
  return f;
}
void main()
{
 int i,n;
 float a,b,x,e,t,p;
 clrscr();
 printf(" Type a and b\n");
 scanf("%d%d",&a,&b);
 printf(" Type maximum no. of interval n\n");
 scanf("%d", &n);
 printf(" Type the value of e\n");
 scanf("%f",&e);
 p=root(a)*root(b);
 if(p>0)
  printf(" Root does not lie between a and b");
 else
  {
   i=1; t=1;
   while(t>e && i<=n)
   {
    x=(a+b)/2;
    if(root(x)*root(a)>0)
    a=x;
    else
    b=x;
    t=fabs(a-b);
    if(fabs(root(x)))
     t=fabs(root(x));
     i++;
    }
    if(i>n)
    printf(" Iteration does not converge");
    else
     {
     printf(" approximate root = %8.4f\n",x);
     printf( " Number of iteration = %d\n",i);
     }
   }
   getch();
   }