先把输入一个个都存入一个string,而后遍历string,判断是否为符号,若是是加号就加上后面的数,减号则减去后面的数。python
在实现的过程当中有许多细节须要注意。例如先把符号存起来,判断符号的位置、是否为最后一个符号了等。app
#!/usr/bin/env python3 # -*- coding: utf-8 -*- """ Created on Wed Mar 20 18:17:30 2019 huawei1 @author: youxinlin """ aStr = '' while True: tmp = input() if tmp != '=': aStr += tmp else: break index = 0 jiaList=[] jianList=[] flagList = [] for i in aStr: if i =='+': jiaList.append(index) flagList.append(index) if i =='-': jianList.append(index) flagList.append(index) index += 1 res = int(aStr[0:flagList[0]])#初始化结果 for i in range(len(flagList)): if flagList[i] in jiaList: if i+1 < len(flagList): res += int(aStr[flagList[i]+1:flagList[i+1]]) else: res += int(aStr[flagList[i]+1:]) elif flagList[i] in jianList: if i+1 < len(flagList): res -= int(aStr[flagList[i]+1:flagList[i+1]]) else: res -= int(aStr[flagList[i]+1:]) print(res)