#include <stdio.h>
#include <iostream>
#include <stdlib.h>
#include <math.h>
using namespace std;

#define n 2


double f(double *x)
{
	int i;
	double output=0;
     for (i=0; i<n;i++)
	{
		output +=(x[i]-2)*(x[i]-2);
	}
	return output;
}
int coorddescent (double pas, double alfa, double epsilon, double *x)
{
	int i;
	float out;
	int steps=0;
	double dist = 10*epsilon;
	int directie=1;
	int x1[n];
	int x2[n];
	while (dist>=epsilon)
	{

		for(i=0;i<n;i++)
		{
			x1[i]=x[i];
			out=f(x);
			directie=1;
			x[i]=x[i]+directie*pas;
			steps++;
			if (out<f(x))
			{
				directie= -1;
				x[i]=x[i]+directie*pas;
				steps++;
			}
			printf ("out=%f, f=%f, directie=%d\n",out, f(x),directie);
			while (out >= f(x))
			{
				out= f(x);
				x[i]=x[i]+directie*pas;
				steps++;
				printf ("out=%f, f=%f, dist=%f\n",out, f(x),dist);
			}
			x2[i] = x[i];
			printf("x[%d]=%f\n",i,x[i]);

		}
		for(int j=0;j<n;j++)
		{
			dist += (x1[j]-x2[j])*(x1[j]-x2[j]);
		}
		dist = sqrt(dist);
		pas=pas*alfa;
		printf("pas=%f\n\n",pas);
		dist = 0;

	}

	return steps;
}

 int main ()
 {
 	int i;
 	double pas=1;
 	double alfa=0.5;
 	double epsilon=0.0001;
 	double x[n]={10.5 , 10};
 	printf("steps= %d\n ", coorddescent(pas, alfa,epsilon,x));
 	for (i=0; i<n;i++)
 	{
 		printf("x[%d] =%2.5f\n",i , x[i]);
	}

 	system("pause");
 	return 0;


 }