Array ( [0] => Array ( [title] => L18A [link] => https://www.youtube.com/embed/aR6AxKwvuo0 ) [1] => Array ( [title] => L18B [link] => https://www.youtube.com/embed/31QD2Per4c0 ) [2] => Array ( [title] => L18C [link] => https://www.youtube.com/embed/Rr0_4Rr4jdA ) [3] => Array ( [title] => L18D [link] => https://www.youtube.com/embed/pV_zYT_Mev0 ) ) 國立清華大學開放式課程OpenCourseWare(NTHU, OCW) - 第18R講 Combination & Permutation -L18_A Combination & Permutation