PRINT
PRINT "＜ 式入力による四則演算 ＞"
PRINT "　　　入力例： (5*6/(-2-1)-7)*(-3+8/4)"
PRINT
LET K=1
OPTION BASE 0
DIM W$(60),WW(60)
INPUT PROMPT "数式を入れてください →  ":Q$
LET QQ$=Q$
IF Q$(1:1)="-" THEN
   LET Q$="0"&Q$
END IF
LET P=LEN(Q$)
FOR i=P*2 TO 1 STEP -1
   IF Q$(i:i)="(" THEN
      FOR j=i TO P*2
         IF Q$(j:j)=")" THEN
            EXIT FOR
         END IF
      NEXT j
      LET W$(K)=Q$(i+1:j-1)
      LET WW(K)=KEISAN(W$(K))
      LET Q$=Q$(1:i-1)&STR$(WW(K))&Q$(j+1:P)
      FOR j=1 TO LEN(Q$)-1
         IF Q$(j:j)="+" AND Q$(j+1:j+1)="-" THEN
            LET Q$(j:j)=""
            EXIT FOR
         END IF
         IF Q$(j:j)="-" AND Q$(j+1:j+1)="-" THEN
            LET Q$(j:j)="+"       
            LET Q$(j+1:j+1)=""
            EXIT FOR
         END IF
      NEXT j
      LET K=K+1
   END IF
NEXT i
PRINT
PRINT " 正解は　 ";KEISAN(Q$)
PRINT    
END
 
EXTERNAL FUNCTION KEISAN(S$)
DIM M$(30),KIG(30),SS(30),G(30)
MAT KIG=ZER
IF S$(1:1)="-" THEN
   LET S$="0"&S$
END IF
LET C=1
LET F=0
FOR i=1 TO LEN(S$)
   IF S$(i:i)="-" OR S$(i:i)="+" THEN
      IF S$(i-1:i-1)="/" OR S$(i-1:i-1)="*" THEN GOTO 10
      IF S$(i+1:i+1)="/" OR S$(i+1:i+1)="*" THEN GOTO 10
      IF S$(i:i)="-" THEN LET KIG(C)=1
      LET M$(C)=S$(1:i-1)
      LET S$=S$(i+1:LEN(S$)-F)
      LET H1=LEN(S$)-F
      LET C=C+1
      LET F=F-i
      LET i=1
   END IF
10 NEXT i
   IF S$(1:1)="-" THEN
      LET S$=S$(2:H1)
      LET G(C-1)=1
   END IF
   LET M$(C)=S$
   FOR i=1 TO C
      LET SS(i)=KAKEWARI(M$(i))
   NEXT i
   LET X=SS(1)
   FOR i=1 TO C
      IF KIG(i)=1 THEN
         LET X=X-SS(i+1)
      ELSE
         LET X=X+SS(i+1)
      END IF
   NEXT i
   IF G(C)=1 THEN
      LET X=X-2*SS(C+1)
   END IF
   LET KEISAN=X
END FUNCTION 

EXTERNAL FUNCTION KAKEWARI(S$)
   DIM M$(30),KIG(30),G(30)
   MAT KIG=ZER
   MAT G=ZER
   LET R=0
   LET C=1
   LET F=0
   FOR i=1 TO LEN(S$)
      IF S$(i:i)="/" OR S$(i:i)="*" THEN
         IF S$(i:i)="/" THEN LET KIG(C)=1
         LET M$(C)=S$(1:i-1)
         IF M$(C)(1:1)="-" THEN
            LET M$(C)=M$(C)(2:i-1)
            LET G(C)=1
         END IF
         LET S$=S$(i+1:LEN(S$)-F)
         LET H2=LEN(S$)-F
         LET C=C+1
         LET F=F-i
         LET i=1
      END IF
   NEXT i
   IF C=1 THEN
      IF S$(1:1)="-" THEN
         LET S$=S$(2:LEN(S$))
         LET G(1)=1
      END IF
   ELSE 
      IF S$(1:1)="-" THEN
         LET S$=S$(2:H2)
         LET G(C-1)=1
      END IF
   END IF
   LET M$(C)=S$
   LET Z=VAL(M$(1))
   FOR i=1 TO C-1
      IF KIG(i)=1 THEN 
         IF G(i)=1 THEN
            IF VAL(M$(i+1))=0 THEN
               PRINT "「 0 では割れません。」"
               BREAK
            END IF
            LET Z=-1*Z/VAL(M$(i+1))
         ELSE
            IF VAL(M$(i+1))=0 THEN
               PRINT "「 0 では割れません。」"
               break
            END IF            
            LET Z=Z/VAL(M$(i+1))
         END IF
      ELSE
         IF G(i)=1 THEN
            LET Z=-1*Z*VAL(M$(i+1))
         ELSE 
            LET Z=Z*VAL(M$(i+1))
         END IF
      END IF
   NEXT i
   LET KAKEWARI=Z
10 END FUNCTION