Structures: Write a program to simulate the time using 'structures'

/*   Write a program to simulate the time using 'structures' */
#include < stdio.h >

    typedef struct {
        int hr;
        int min;
        int sec;
    }
CLOCK;

//    Function Declaration
void increment(CLOCK * clock);
void show(CLOCK * clock);

int main(void) {
        //    Local Declaration
        CLOCK clock = {
            14,
            38,
            56
        };
        int i;

        //    Statements
        for (i = 0; i < 6; ++i) {
            increment( & clock);
            show( & clock);
        } // for
        return 0;
    } // main

/*    ==================== increment ====================
    This function accepts a pointer to clock and 
    increments the time by one second.
       Pre   previous clock setting
       Post  clock incremented by one second.
*/
void increment(CLOCK * clock) {
        //    Statements
        (clock - > sec) ++;
        if (clock - > sec == 60) {
            clock - > sec = 0;
            (clock - > min) ++;
            if (clock - > min == 60) {
                clock - > min = 0;
                (clock - > hr) ++;
                if (clock - > hr == 24)
                    clock - > hr = 0;
            } // if 60 min
        } // if 60 sec
        return;
    } // increment

/* ====================== show ======================
    This function shows the current time in military form.
       Pre   clock time
       Post  clock time displayed
*/
void show(CLOCK * clock) {
        //    Statements
        printf("%02d:%02d:%02d\n",
            clock - > hr, clock - > min, clock - > sec);
        return;
    } // show

/*    Results:
14:38:57
14:38:58
14:38:59
14:39:00
14:39:01
14:39:02
*/