/*-----------------------------------------------------------------------------------------
* Project Name   : Report04.2 - polynomial expression(Struct)
* Programmed by  : Young Min Jo
* Student Number : 2008060021
* Date           : Sunday 6 April 2014
* (c) Copyright by Department of Computer Education at Chungbuk
*     National University, Chungbuk, Republic of Korea
------------------------------------------------------------------------------------------*/
#include "stdafx.h"
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define MAX 100

typedef struct term{
	float coef;
	int expon;
};

/*-------------------------------------- calculate ----------------------------------------
/* Function : 변수 xval에따른 다항식 계산
------------------------------------------------------------------------------------------*/
float calculate(term *poly, int count, float xval){

	float result = 0;

	for (int i = 0; i <= count; i++){
		result += poly[i].coef * pow(xval, poly[i].expon);
	}
	return result;
}

/*--------------------------------------- addpoly -----------------------------------------
/* Function : 변수 xval에따른 다항식 두개의 계산 합
------------------------------------------------------------------------------------------*/
float addpoly(term *poly1, int count1, term *poly2, int count2, float xval){

	term poly[MAX] = { 0 };
	int result = 0;
	int count = 0;
	int i = 0;
	int j = 0;

	
	while (i < count1 && j < count2){
		//다항식 지수가 같을때 계수를 더해서 저장하고 두개의 다항식 index 증가
		if (poly1[i].expon == poly2[j].expon){
			poly[count].coef = poly1[i].coef + poly2[j].coef;
			poly[count].expon = poly2[j].expon;
			count++;
			i++;
			j++;
		}
		//다항식 지수가 다를때 지수가 작은쪽의 계수 저장과 index 증가
		else if (poly1[i].expon > poly2[j].expon){
			poly[count].coef = poly2[j].coef;
			poly[count].expon = poly2[j].expon;
			count++;
			j++;
		}
		else{
			poly[count].coef = poly1[i].coef;
			poly[count].expon = poly1[i].expon;
			count++;
			i++;
		}
	}

	//두개 다항식 비교후 최고차가 더큰 다항식의 나머지 계산
	for (; i < count1; i++){
		poly[count].coef = poly1[i].coef;
		poly[count].expon = poly1[i].expon;
		count++;
	}
	for (; j < count2; j++){
		poly[count].coef = poly2[j].coef;
		poly[count].expon = poly2[j].expon;
		count++;
	}

	result = calculate(poly, count, xval);

	return result;
}

//Menu
void Menu(){
	printf("*****Polynomial Expression(Struct)*****\n");
	printf("1. Poly1\n");
	printf("2. Poly2\n");
	printf("3. Poly1 + Poly2\n");
	printf("4. EXIT\n");
}

void main(){

	FILE *infp1, *infp2;
	int i;
	int check;
	float x, result;
	term poly1[MAX] = { 0 };
	term poly2[MAX] = { 0 };
	int count1, count2;// 계수의 개수

	//*.txt에서 계수의 개수와 지수와 지수에 해당되는 계수를 받음
	infp1 = fopen("poly1(struct&linkedlist).txt", "r");
	if (infp1 == NULL){
		printf("파일없음");
		exit(0);
	}
	infp2 = fopen("poly2(struct&linkedlist).txt", "r");
	if (infp2 == NULL){
		printf("파일없음");
		exit(0);
	}
	fscanf(infp1, "%d", &count1);
	fscanf(infp2, "%d", &count2);
	if (count1 > MAX || count2 > MAX){
		printf("계수의 개수가 너무 많습니다.\n");
		exit(0);
	}
	for (i = 0; i < count1; i++){
		fscanf(infp1, "%f %d", &poly1[i].coef, &poly1[i].expon);
	}
	for (i = 0; i < count2; i++){
		fscanf(infp2, "%f %d", &poly2[i].coef, &poly2[i].expon);
	}
	fclose(infp1);
	fclose(infp2);

	while (1){
		Menu();
		printf("메뉴 번호 입력 : ");
		scanf("%d", &check);

		switch (check){

		case 1:
			printf("x 값 : ");
			scanf("%f", &x);
			result = calculate(poly1, count1, x);
			printf("Poly1 : %0.1f\n", result);
			break;

		case 2:
			printf("x 값 : ");
			scanf("%f", &x);
			result = calculate(poly2, count2, x);
			printf("Poly2 : %0.1f\n", result);
			break;

		case 3:
			printf("x 값 : ");
			scanf("%f", &x);
			result = addpoly(poly1, count1, poly2, count2, x);
			printf("Poly1 + Poly2 : %0.1f\n", result);
			break;

		case 4:
			exit(0);

		default:
			break;
		}
	}
}