C生成随机简单运算式

1、#include <iostream>#include <stdlib. h>#include <ctime>nclude <conio. h>using std:cin;using std:cout;using std:endl;/计算式数量int const Num = 100;/计算式中最大数int const MCum = 100;/每题分数int const PerMark = 1;/计算结果最大值int const MaxResult = 100;/计算结果最小值int const MinResult = 0;enum enOpAdd

2、, Subtract, Multiply, Divide;/将枚举类型转换为字符类型，以便输出。char enum2char (enOp op)switch (op)case Add:return ' +'case Subtract:return ' -'；case Multiply:return ' x ;case Divide：return ，;return ''计算生成表达式的正确结果。int myResult(int left,int right, enOp op)switch (op)case Add:return left+r

3、ight;case Subtract:return left-right:case Multiply:return left*right;case Divide:return left/right;return 0;检査生成计算式的正确与否。其中减法结果不能为负数，除法结果不能为小数。bool checkFormula(int left, int right, enOp op)switch (op)case Add:return true;case Subtract:if(left < right) return false; return true;case Multiply:retu

4、rn true;case Divide:if(right = 0)return false;if(double(left/right) !二 double(double(left)/double(right)return false;return true;return false;依据给定操作符，生成符合条件的表达式。void getFormula(int* left, int*:right, enOp op)/srand(time(NULL);*left 二 1 + rand () % MaxNum:*right = 1 + rand () % MaxNum;if(checkFormula

5、(*left, bright, op) && myResult(*left, bright, op)<= MaxResult && myResult(*left, *right, op)>= MinResult)break;int main()/操作符左值int leftNum;操作符右值int rightNum;/用户输入计算结果int resultum;/操作符+r/enOp operNum;/正确答案个数int answerRight = 0;cout«"正在生成，请稍等。"«endl;随机种子srand

6、(t ime(NULL);开始生成汁算表达式。for (int i 二 0;iNum;i+)/srand( (unsigned)time(NULL);/操作符oper i = enOp(rand()%4);getFormula(&lefti, ighti, operi); cout«"生成计算式完成，开始答题！ "endl;/输出表达式，让用户答题for (int i = 0;i<Num;i+)/输出表达式cout«"第题：n"cout«lefti<<J J <<enum2char(op

7、eri)«J * <<righti<<= ”；/获取用户答案cin>>result i;/比对用户答案是否.止确，止确输出right, answerRigth加一，否则输出not correctoif(resulti二二 myResult(lefti, righti, operi)cout<<，Right! n"answerRight+;elsecout<<，Not correct! n"/全部答题完毕，输出正确答案个数及得分。cout«"终止答题，共题，每题，«PerMark&#