杭州交通信息网盐酸镁粉反应原理:如何掌握运算~
来源：百度文库 编辑：杭州交通信息网 时间：2024/05/09 18:51:02
数学的简便运算和方程........准备上初中了,但是除了简单的简便运算和..简单的方程...稍微难点的都不会算.......~怎么才能让自己更好的掌握...?
汗...问你老师撒...
这里有段QB程序,帮你解决简便混合运算:
CLS
INPUT a$
l = LEN(a$)
DIM b$(l), s(l)
FOR i = 1 TO l
c$ = MID$(a$, i, 1)
IF c$ = "+" OR c$ = "-" OR c$ = "*" OR c$ = "/" OR c$ = "^" THEN
d = d + 1
b$(d) = c$
s(d) = VAL(s$)
s$ = ""
ELSE
s$ = s$ + c$
END IF
NEXT i
d = d + 1
s(d) = VAL(s$)
FOR i = 1 TO d
IF b$(i) = "^" THEN s(i) = s(i) ^ s(i + 1): GOSUB e
NEXT i
FOR i = 1 TO d
IF b$(i) = "*" THEN s(i) = s(i) * s(i + 1): GOSUB e
IF b$(i) = "/" THEN s(i) = s(i) / s(i + 1): GOSUB e
NEXT i
FOR i = 1 TO d
IF b$(i) = "+" THEN s(i) = s(i) + s(i + 1): GOSUB e
IF b$(i) = "-" THEN s(i) = s(i) - s(i + 1): GOSUB e
NEXT i
PRINT a$; "="; s(1): END
e: FOR f = i TO l - 2
b$(f) = b$(f + 1)
s(f + 1) = s(f + 2)
NEXT f
d = d - 1
i = i - 1
RETURN