Fixed-Point Iteration. Root finding.

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C

I am trying to write a program to find roots using Fixed Point Iteration method and I am getting zero everytime I run this. entering p0=1, Tol=.01

Could someone please help? I tried to follow the algorithm in the book, but I am still new to programming and not good at reading them. Thank you in advance.


Algorithm:

INPUT initial approximation p0; tolerance TOL; maximum number of iterations N0.
OUTPUT approximate solution p or message of failure.

Step 1 Set i=1.
Step 2 While i <= N0 do Steps 3-6.
Step 3 Set p=g(p0). (Compute pi.)
Step 4 If |p-p0|<tol mode="hold"> OUTPUT (p); (The procedure was successful.)
STOP.
Step 5 Set i=i+1.
Step 6 Set p0=p. (Update p0.)
Step 7 OUTPUT ('The method failed after N0 iterations, N0=', N0);
(The procedure was unsuccessful.)
STOP.

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

double f(double x)
{
return x*x*x*x-3*x*x-3;  //change equation for each problem
}

int main()
{
    double p, p0, Tol;
    int i=1;
    int No;

    printf("Enter approximate p: ");
    scanf ("%lf", &p0);

    printf("Desired Tolerance: ");
    scanf ("%lf", &Tol);

    printf("Maximum Iterations: ");
    scanf ("%d", &No);


    while (i<=No)
    {
        p = p0;

        if((fabs(p-p0))<Tol)
        {
            printf("%lf", &p);
            break;
        }
        printf("Iteration %d: Current value = %lf\n", i, p);

        i++;  //i=i+1
        p0=p;

        if (i>No)
        {
        printf("Method Failed after %d", No);
        printf(" iterations");
        }

Here is the updated one:

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

double f(double x)
{
return x*x*x*x-3*x*x-3;  //change equation for each problem
}

double g(double x)
{
return pow(3*x*x+3,.25);
}

int main()
{
    double p, p0, Tol;
    int i=1;
    int No;

    printf("Enter approximate p: ");
    scanf ("%lf", &p0);

    printf("Desired Tolerance: ");
    scanf ("%lf", &Tol);

    printf("Maximum Iterations: ");
    scanf ("%d", &No);


    while (i<=No)
    {
        p = g(p0);

        if((fabs(p-p0))<Tol)
        {
            //printf("%lf", &p);
            break;
        }
        printf("Iteration %d: Current value = %lf\n", i, p);

        i++;  //i=i+1
        p0=p;

        if (i>No)
        {
        printf("Method Failed after %d", No);
        printf(" iterations");
        }

    }

}