Bisection_Method.cpp

/* Bisection Method */
#include<iostream>
#include<iomanip>
#include<math.h>
using namespace std;
float f(float x){
    return (x*x*x - 4*x -9);
}
void bisect(float *x,float a,float b,int *itr){
    *x = (a+b)/2;
    ++(*itr);
    cout<<"Iteration no."<<setw(3)<<*itr
    <<"X = "<<setw(7)<<setprecision(5)
    <<*x<<endl;
}
int main(){
    int itr = 0,maxitr;
    float x,a,b,aerr,x1;
    cout<<"Enter the values of a,b,"
    <<"allowed error, maximum iterations"<<endl;
    cin>> a >> b >> aerr >> maxitr;
    cout<<fixed;
    bisect(&x,a,b,&itr);
    do{
        if(f(a)*f(x) < 0) b = x;
        else a = x;
        bisect(&x1,a,b,&itr);
        if(fabs(x1-x) < aerr){
            cout<<"After "<< itr <<" iteration, root "
            <<"="<< setw(6)<< setprecision(4)
            <<x1 << endl;
            return 0;
        }
        x = x1;
    }while(itr < maxitr);
    cout<<"Solution does not converge,"
    <<"iteration not sufficient"<<endl;
    return 1;
}