/* pier: Pier usage

   Example:

   	Enter command: i 20
	Enter command: i 43
	Enter command: l
	Pier length 100, used 63
	Enter command: o 20
	Enter command: i 40
	Enter command: l
	Pier length 100, used 83
	Enter command: o 0
	Enter command: l
	Pier length 100, used 43
	Enter command: q
	The longest ship was 43.
*/

#include <stdio.h>

int pier_length = 100, INT_used = 0,
    SHIP = 0, last_ship = 0, longest;

char CHAR_command;

int main (void) {

   longest = 0;

   printf("Enter command: "); scanf("%c", &CHAR_command);

   while (CHAR_command != 'q') {
   	switch (CHAR_command) {

	case 'i': /* Ship in */

		scanf("%d", &SHIP);
		if (SHIP == 0) SHIP = last_ship;
		last_ship = SHIP;
		INT_used += SHIP;
		if (INT_used > pier_length)
		    printf("Pier length exceeded.\n");
		if (SHIP > longest) longest = SHIP;
		break;

	case 'o': /* Ship out */

		scanf("%d", &SHIP);
		if (SHIP == 0) SHIP = last_ship;
		last_ship = SHIP;
		INT_used -= SHIP;
		break;

	case 'l': /* List */

		printf("Pier length %d, used %d\n",
		        pier_length, INT_used);
		break;
   	}

	printf("Enter command: ");
	do scanf("%c", &CHAR_command); while (CHAR_command == '\n');
   }

   printf("The longest ship was %d.\n", longest);

   return(0);
}

   	Modify the above program to reserve for each vessel 
   	extra pier space of 10 per cent of its own length.