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

int checkFloat(float b);
float mySqrt(float a);
main(){
	float a;
	while(1){
	printf("Parakalo doste enan pragmatiko arithmo\n");
	scanf("%f", &a);
	if(checkFloat(a) == 0)
		printf("parakalo doste thetiko pragmatiko arithmo\n");
	else
		break;
	}

	printf("i riza toy %f ine i %f simfwna me tin sqrt, tis math.h\n", a, sqrt(a));
	printf("i riza toy %f simfwna me ti dikia moy sinartisi ine i %f\n", a, mySqrt(a));
	printf("i diafora tis rizas apo tin sinartisi  sqrt kai apo tin dikia moy sinartisi ine i %f :\n", mySqrt(a) - sqrt(a)); 
}
	

int checkFloat(float b){
	if(b < 0)
		return 0;
	else
		return 1;
}


float mySqrt(float a){
	float x, b;
	//printf("aaa %f\n", a);
	int n;
	n = 1;
	while(1){
		x = 0.5*(n + a/n);
		//printf("%f \n", x);
		if(n > 1){
			if(x - ((1/2)*((n-1)+a/(n-1))) < 10^-1) 
				break;
		}
	n++;
	}
	//printf("i riza  toy %f simfwna me ti dikia moy sinartisi ine i %f \n",a,  x);
	return x;
}