JOI2008予選 問題2@Scheme
今日はここまで。文字列処理むずい。
(define (count-substring str sub) (define (count-substring-sub2 strl subl count) (if (null? subl) (+ count 1) (if (null? strl) count (if (char=? (car strl) (car subl)) (count-substring-sub2 (cdr strl) (cdr subl) count) count)))) (define (count-substring-sub strl subl count) (if (null? strl) count (count-substring-sub (cdr strl) subl (count-substring-sub2 strl subl count)))) (count-substring-sub (string->list str) (string->list sub) 0)) (let ((input-string (symbol->string (read)))) (print (count-substring input-string "JOI")) (print (count-substring input-string "IOI")))