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

float celtofah(float x)
{
	return (x * 9/5) + 32; 
}

float celtokelv(float x)
{
        return x + 273.15;
}

float celtorank(float x)
{
	return (celtofah(x)) + 459.67;
}






float fahtocel(float x)
{
	return (x - 32) * 5/9;
}

float fahtokelv(float x)
{
        return (fahtocel(x)) + 273.15;
}

float fahtorank(float x)
{
	return x + 459.67;
}






float kelvtocel(float x)
{
        return x - 273.15;
}

float kelvtofah(float x)
{
        return celtofah((kelvtocel(x)));
}

float kelvtorank(float x)
{
	return (kelvtofah(x)) + 459.67;
}






float ranktocel(float x)
{
	return fahtocel(x - 459.67);
}

float ranktofah(float x)
{
	return x - 459.67;
}

float ranktokelv(float x)
{
	return fahtokelv(x - 459.67);
}




int main(void)
{
	char choice[2];
	float num = 0;
	while ( (strcasecmp("q", choice)) != 0 )
	{
		strcpy(choice, "");
		printf("1. Celsius.\n");
		printf("2. Fahrenheit.\n");
		printf("3. Kelvin\n");
		printf("4. Rankine\n");
		printf("Q to quit.\n");
		printf("Input:");
		scanf("%s", &choice);
	
		if ((strcmp("1", choice)) == 0)
		{
			printf("1. Fahrenheit.\n");
			printf("2. Kelvin.\n");
			printf("3. Rankine.\n");
			printf("Output:");
			scanf("%s", &choice);
			if ((strcmp("1", choice)) == 0)
			{
				printf("Please enter Celsius number for conversion:");
				scanf("%f", &num);
				printf("%g Degrees Fahrenheit\n", (celtofah(num)));
			}
			if ((strcmp("2", choice)) == 0)
			{
				printf("Please enter Celsius number for conversion:");
				scanf("%f", &num);
				printf("%g Degrees Kelvin\n", (celtokelv(num)));
				
			}
			if ((strcmp("3", choice)) == 0)
			{
				printf("Please enter Celsius number for conversion:");
				scanf("%f", &num);
				printf("%g Degrees Rankine\n", (celtorank(num)));
			}
		}	
	
		if ((strcmp("2", choice)) == 0)
		{
			printf("1. Celsius\n");
			printf("2. Kelvin\n");
			printf("3. Rankine\n");
			printf("Output:");
			scanf("%s", &choice);
			
			if ((strcmp("1", choice)) == 0)
			{
				printf("Please enter Fahrenheit number for conversion:");
				scanf("%f", &num);
				printf("%g Degrees Celsius\n", (fahtocel(num)));
			}
			
			if ((strcmp("2", choice)) == 0)
			{
				printf("Please enter Fahrenheit number for conversion:");
				scanf("%f", &num);
				printf("%g Degrees Kelvin\n", (fahtokelv(num)));
			}
			
			if ((strcmp("3", choice)) == 0)
			{
				printf("Please enter Fahrenheit number for conversion:");
				scanf("%f", &num);
				printf("%g Degrees Rankine\n", (fahtorank(num)));
			}
		}
		if ((strcmp("3", choice)) == 0)
		{
			printf("1. Celsius\n");
			printf("2. Fahrenheit\n");
			printf("3. Rankine\n");
			printf("Output:");
			scanf("%s", &choice);
			if ((strcmp("1", choice)) == 0)
			{
				printf("Please enter Kelvin number for conversion:");
				scanf("%f", &num);
				printf("%g Degrees Celsius\n", (kelvtocel(num)));
				
			}

			if ((strcmp("2", choice)) == 0)
			{
				printf("Please enter Kelvin number for conversion:");
				scanf("%f", &num);
				printf("%g Degrees Fahrenheit\n", (kelvtofah(num)));
			}

			if ((strcmp("3", choice)) == 0)
			{
				printf("Please enter Kelvin number for conversion:");
				scanf("%f", &num);
				printf("%g Degrees Rankine\n", (kelvtorank(num)));
			}
		}

		if ((strcmp("4", choice)) == 0)
		{
                        printf("1. Celsius\n");
                        printf("2. Fahrenheit\n");
                        printf("3. Kelvin\n");
                        printf("Output:");
			scanf("%s", &choice);
			if ((strcmp("1", choice)) == 0)
			{
				printf("Please enter Rankine number for conversion:");
				scanf("%f", &num);
				printf("%g Degrees Celsius\n", (ranktocel(num)));
			}

			if ((strcmp("2", choice)) == 0)
			{
				printf("Please enter Rankine number for conversion:");
				scanf("%f", &num);
				printf("%g Degrees Fahrenheit\n", (ranktofah(num)));

			}

			if ((strcmp("3", choice)) == 0)
			{
				printf("Please enter Rankine number for conversion:");
				scanf("%f", &num);
				printf("%g Degrees Kelvin\n", (ranktokelv(num)));
			}

		}



		}

	return 0;
}