assignment B_input

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef enum {false, true} bool;

bool dupcheck_code(char a[11], int k) { /* check duplicate a in array bkinstck[].code which have k elements */
    int i;
    for (i = 0; i<k; i++) {
        if (strcmp(bkinstck[i].code, a) == 0) {
            return(true);
        }
    }
    return(false);
}

void input_code(int i) { /* input bkinstck[i].code */
    char a[11];

    while (1) {
        printf(" Enter code (enter STOP to stop): ");
        fflush(stdin);
        gets(a);
        //scanf("%[^\n]", a);
        if ((strlen(a) > 0) && (strlen(a) <= 10)) {
            if (dupcheck_code(a, i) == true) {
                printf(" The code %s already exists, please re-enter!\n", a);
            }
            else {
                strcpy(bkinstck[i].code, a);
                break;
            }
        }
        else {
            printf(" Invalid code, please re-enter!\n");
        }
    }
}