#include<stdio.h>
#define N 20
float f1(float,float);
void ModEuler(float(*f1)(float ,float),float x0,float y0,float xn,int n){
	int i;
	float yp,yc,x=x0,y=y0,h=(xn-x0)/n;
	printf("x[0]%f\ty[0]=%f\n",x,y);
	for(i=1;i<=n;i++){
		yp=y+h*f1(x,y);
		x=x0+i*h;
		yc=y+h*f1(x,yp);
		y=(yp+yc)/2.0;
		printf("x[%d]=%f\ty[%d]=%f\n",i,x,i,y);
	}
}
void main(){
	float xn=5.0,x0=0.0,y0=2.0;
	//void ModEuler(float(*)(float,float),float,float,float,int);
	//float f1(float,float);
	ModEuler(f1,x0,y0,xn,N);
}
float f1(float x,float y){
	return -x*y*y;
}