Таблица умножения

#include <stdio.h>
#include <Windows.h>
#include <tchar.h>
typedef size_t index_t;
#define DEC 10
enum position {
    TOP,
    CENTER,
    BOTTOM,
    HORIZONTAL      = 196,
    TOP_LEFT        = 218,
    TOP_CENTER      = 194,
    TOP_RIGHT       = 191,
    CENTER_LEFT     = 195,
    CENTER_CENTER   = 197,
    CENTER_RIGHT    = 180,
    BOTTOM_LEFT     = 192,
    BOTTOM_CENTER   = 193,
    BOTTOM_RIGHT    = 217,
    VERTICAL        = 179
};
void table(enum position, unsigned);
int main() {
    index_t _col, _row, _multiplication;
    const unsigned _size = 10;
    SetConsoleTitleW(_T("Таблица умножения"));
    system("color 9B");
    table(TOP, _size);
    for (_row = 0; _row < _size; _row++) {
        for (_col = 0; _col < _size; _col++) {
            if (!_row && !_col) printf("%c  ", VERTICAL);
            else if (!_row) printf("%c %i", VERTICAL, _col);
            else if (!_col) printf("%c %i", VERTICAL, _row);
            else {
                _multiplication = _col * _row;
                if (_multiplication < DEC) printf("%c %i", VERTICAL, _multiplication);
                else printf("%c%i", VERTICAL, _multiplication);
            }
        }
        printf("%c\n", VERTICAL);
        if (_row < _size - 1) table(CENTER, _size);
    }
    table(BOTTOM, _size);
    getchar();
    return 0;
}
void table(enum position __line, unsigned __cols) {
    unsigned char _left, _center, _right, _current;
    size_t _width = __cols * 3 + 1;
    index_t _n;
    switch (__line) {
        case TOP:
            _left   = TOP_LEFT;
            _center = TOP_CENTER;
            _right  = TOP_RIGHT;
            break;
        case CENTER:
            _left   = CENTER_LEFT;
            _center = CENTER_CENTER;
            _right  = CENTER_RIGHT;
            break;
        case BOTTOM:
            _left   = BOTTOM_LEFT;
            _center = BOTTOM_CENTER;
            _right  = BOTTOM_RIGHT;
            break;
        default: printf("Error: __line argument does not exist\n\a");
    }
    for (_n = 0; _n < _width; _n++) {
        if (!_n) _current = _left;
        else if (_n == _width - 1) _current = _right;
        else if (!(_n % 3)) _current = _center;
        else _current = HORIZONTAL;
        printf("%c", _current);
    }
    printf("\n");
}