# include < stdio . h >// 구구단 함수 . void multiful ( int mult ) { int y = 1 ; while ( y < 9 ) { while ( y < 10 ) { printf ( "% d *% d = % d \ n ", mult , y , mult * y ) ; y ++; } }}// 메인 시작 int main ( void ) { int i = 1 , j = 0 ; printf ( " 구구단 계산기 \ n "); while ( i ! = 0 ) { scanf ( "% d ", & i ) ; printf ( "*** 결과 ***\ n "); switch ( i ) { case 2 : { multiful ( i ) ; break ;} case 3 : { multiful ( i ) ; break ;} case 4 : { multiful ( i ) ; break ;} case 5 : { multiful ( i ) ; break ;} case 6 : { multiful ( i ) ; break ;} case 7 : { multiful ( i ) ; break ;} case 8 : { multiful ( i ) ; break ;} case 9 : { multiful ( i ) ; break ;} case 0 : break ; } if ( i ! = 0 ) continue ; else break ; } return 0 ;}