This program is to teach beginner to understand 1-lookup talbe 2-external variable 3-array 4-structure 5-return datatype

lookupTable.c

/*
	This program is to teach beginner 
	to understand
	1-lookup talbe
	2-external variable
	3-array
	4-structure
	5-return datatype

	 
	Programmer: Dr. Aung Win Htut (Green Hackers)
	https://www.facebook.com/GreenHackersOTC/
	Date: 13-04-2018
	
*/
#include<stdio.h>
#include<conio.h>

struct TRIGO trigoval(int ang);

int ang=45;
int index=-1;
int angle[8]	=	{	0,	30,		45,		60,	    90,		180,	270,	360	};
float sine[8]	=	{	0,	0.5,	0.707,	0.866,  1,		0,		-1,		0	};    //1/sqrt(2)=0.707  sqrt(3)/2 =0.866
float cosine[8] =	{	1,	0.866,	0.707,	0.5,	0,		-1,		0,		1	};    //1/sqrt(2)=0.707  sqrt(3)/2 =0.866

struct TRIGO{
	float sin;
	float cos;
};

int main()
{
	TRIGO tgo;
	tgo = trigoval(ang);
	
	printf("sin(%d)=%f cos(%d)=%f",ang,tgo.sin ,ang,tgo.cos );

	getch();
	return 0;
}


struct TRIGO trigoval(int ang)
{
	int index=-1;
	struct TRIGO trigo;
	for(int j=0;j<8;j++)
	{
		if(angle[j]==ang)
		{
			index=j;
		}
	}
	trigo.sin =sine[index];
	trigo.cos =cosine[index];
	return trigo;
}