At the Beginning of the Alphabet

Consider the following header file:

myheader.h

1. #ifndef _MYHEADER_H
2. #define _MYHEADER_H 1
3. char foo(const char *);
4. #endif /* myheader.h */

Write the function foo() declared in myheader.h that takes a string as a parameter containing only uppercase letters of the English alphabet. The function should determine and return the letter of the string that is the first in alphabetical order. Make sure that the original string does not change.

Note

Place the function in file foo.c and submit this file as a solution to the evaluation system. You can test your solution using the following files. The evaluation system does not necessarily perform the evaluation using these files.

main.c

1. #include <stdio.h>
2. #include <stdlib.h>
3. #include "myheader.h"
4. int main()
5. {
6.     char line[100];
7.     while (gets(line) != NULL)
8.         printf("%c\n", foo(line));
9.     return EXIT_SUCCESS;
10. }

Makefile

1. SRCS = main.c foo.c
2. OBJS = $(SRCS:%.c=%.o)
3. TARGETS = main
4. .PHONY: clean
5. all: $(TARGETS)
6. main: $(OBJS)
7. $(CC) $(OBJS) -o main
8. %.o: %.c
9. $(CC) -Wall -c $< -o $@
10. clean:
11. rm -rf $(OBJS) *~ $(TARGETS)

Sample Input

1. ALMA
2. MEGGY
3. MOTOR

Output for Sample Input

1. A
2. E
3. M

One possible solution is available in: main.c.