#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/*
Written By : Ahmad Jawed ZAFAR
Date : 1/03/2008
*/

float change_to_number(char *str)
{
	int i=0;
	char string1[5], *string2;

	while (str[i]!='\0')
	{
		i++;

		string1[i-1]=str[i-1];
	}

	string1[i]='\0';
	string2=(char*)malloc((strlen(string1)+1)*sizeof(char));
	strcpy(string2, string1);
	
		if (strcmp(string2, "AA\0")==0 || strcmp(string2, "aa\0")==0)
		{
			return 4;
		}
		if (strcmp(string2, "BA\0")==0 || strcmp(string2, "ba\0")==0)
		{
			return 3.5;
		}

		if (strcmp(string2, "BB\0")==0 || strcmp(string2, "bb\0")==0)
		{
			return 3;
		}

		if (strcmp(string2, "CB\0")==0 || strcmp(string2, "cb\0")==0)
		{
			return 2.5;
		}

		if (strcmp(string2, "CC\0")==0 || strcmp(string2, "cc\0")==0)
		{
			return 2;
		}

		if (strcmp(string2, "DC\0")==0 || strcmp(string2, "dc\0")==0)
		{
			return 1.5;
		}

		if (strcmp(string2, "DD\0")==0 || strcmp(string2, "dd\0")==0)
		{
			return 1;
		}

		else 
			return 0;
}

int main()
{
			struct subject {
				char subject[15], *letter_mark;
				int tot_crd;
			} sub[10];

	int total_sub, total_crd=0, i=0;
	char letter_mark_tmp[5];
	float gpa, total_mark=0.0;
	
	printf("Enter The Total Number Of Subjects\n\n");

	printf("Type Here : ");
	scanf("%d", &total_sub);
	printf("\n");
	
		for (i=0; i<total_sub; i++)
		{
			gets(sub[i].subject);
			printf("Enter Subject %d : ", i+1);
			gets(sub[i].subject);

			printf("Now Enter The Total Credit Devoted To %s : ", sub[i].subject);
			scanf("%d", &sub[i].tot_crd);
			printf("\n");
		}
			
		system("cls");		
		gets(letter_mark_tmp);
		while ((strcmp(letter_mark_tmp, "x\0")!=0) || (strcmp(letter_mark_tmp, "X\0")!=0))
		{		
			for (i=0; i<total_sub; i++)
			{				
				printf("Letter Mark For %s : ", sub[i].subject);
				gets(letter_mark_tmp);

				sub[i].letter_mark=(char*)malloc((strlen(letter_mark_tmp)+1)*sizeof(char));

				strcpy(sub[i].letter_mark, letter_mark_tmp);
			}

				total_mark=0;

				for (i=0; i<total_sub; i++)
				{
					total_mark+=((sub[i].tot_crd)*(change_to_number(sub[i].letter_mark)));
				}

					//in order to count total credit//
				total_crd=0;
				for (i=0; i<total_sub; i++)
				{
					total_crd+=sub[i].tot_crd;
				}
					//end//
					
				gpa=0;
				gpa=(float)(total_mark)/total_crd;
					
				system("cls");

					for (i=0; i<total_sub; i++)
					{
						
						printf("%s		%s\n", sub[i].subject, sub[i].letter_mark);
					}
					printf("\n");

					printf("---------------------\n");
					printf("Your GPA Is  %.2f\n", gpa);
					printf("---------------------\n\n");

				printf("To Calculate Again Press Enter, To Exit Press 'X'\n");
				gets(letter_mark_tmp);

					system("cls");

				if ((strcmp(letter_mark_tmp, "x\0")==0) || (strcmp(letter_mark_tmp, "X\0")==0))
				{
					printf("Thanks For Prefering ZAFARSOFT, Bye\n");
					system("pause");
					return 0;
				}

				system("cls");
		
		}

system("pause");
return 0;
}