四则运算
Posted yifan2016
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这次是结对开发，这是我和同学写的代码，思路是讲字符串里的数字与符号逐渐取出，然后使用数字栈和符号栈逐渐进行调整，算出结果
代码：
// 按要求随机生成四则运算 王世强 2015/3/15 #include<iostream> #include<stdlib.h> #include<iomanip> #include<time.h> #include<stdio.h> #include"math.h" #define true 1 #define false 0 #define OPSETSIZE 7 #define random() (rand()%100000) #include"string.h" typedef int Status; using namespace std; unsigned char Prior[7][7] = { // 运算符优先级表 // \'+\' \'-\' \'*\' \'/\' \'(\' \')\' \'#\' /*\'+\'*/\'>\',\'>\',\'<\',\'<\',\'<\',\'>\',\'>\', /*\'-\'*/\'>\',\'>\',\'<\',\'<\',\'<\',\'>\',\'>\', /*\'*\'*/\'>\',\'>\',\'>\',\'>\',\'<\',\'>\',\'>\', /*\'/\'*/\'>\',\'>\',\'>\',\'>\',\'<\',\'>\',\'>\', /*\'(\'*/\'<\',\'<\',\'<\',\'<\',\'<\',\'=\',\' \', /*\')\'*/\'>\',\'>\',\'>\',\'>\',\' \',\'>\',\'>\', /*\'#\'*/\'<\',\'<\',\'<\',\'<\',\'<\',\' \',\'=\', }; typedef struct StackChar { char c; struct StackChar *next; }SC; //StackChar类型的结点SC typedef struct StackFloat { float f; struct StackFloat *next; }SF; //StackFloat类型的结点SF SC *Push(SC *s,char c) //SC类型的指针Push，返回p { SC *p=(SC*)malloc(sizeof(SC)); p->c=c; p->next=s; return p; } SF *Push(SF *s,float f) //SF类型的指针Push，返回p { SF *p=(SF*)malloc(sizeof(SF)); p->f=f; p->next=s; return p; } SC *Pop(SC *s) //SC类型的指针Pop { SC *q=s; s=s->next; free(q); return s; } SF *Pop(SF *s) //SF类型的指针Pop { SF *q=s; s=s->next; free(q); return s; } float Operate(float a,unsigned char theta, float b) //计算函数Operate { switch(theta) { case \'+\': return a+b; case \'-\': return a-b; case \'*\': return a*b; case \'/\': return a/b; default : return 0; } } char OPSET[OPSETSIZE]={\'+\',\'-\',\'*\',\'/\',\'(\',\')\',\'#\'}; Status In(char Test,char *TestOp) { int Find=false; for (int i=0; i< OPSETSIZE; i++) { if(Test == TestOp[i]) Find= true; } return Find; } Status ReturnOpOrd(char op,char *TestOp) { for(int i=0; i< OPSETSIZE; i++) { if (op == TestOp[i]) return i; } } char precede(char Aop, char Bop) { return Prior[ReturnOpOrd(Aop,OPSET)][ReturnOpOrd(Bop,OPSET)]; } float EvaluateExpression(char* MyExpression) { // 算术表达式求值的算符优先算法 // 设OPTR和OPND分别为运算符栈和运算数栈，OP为运算符集合 SC *OPTR=NULL; // 运算符栈，字符元素 SF *OPND=NULL; // 运算数栈，实数元素 char TempData[20]; float Data,a,b; char theta,*c,Dr[]={\'#\',\'\\0\'}; OPTR=Push(OPTR,\'#\'); c=strcat(MyExpression,Dr); strcpy(TempData,"\\0");//字符串拷贝函数 while (*c!= \'#\' || OPTR->c!=\'#\') { if (!In(*c, OPSET)) { Dr[0]=*c; strcat(TempData,Dr); //字符串连接函数 c++; if (In(*c, OPSET)) { Data=atof(TempData); //字符串转换函数(double) OPND=Push(OPND, Data); strcpy(TempData,"\\0"); } } else // 不是运算符则进栈 { switch (precede(OPTR->c, *c)) { case \'<\': // 栈顶元素优先级低 OPTR=Push(OPTR, *c); c++; break; case \'=\': // 脱括号并接收下一字符 OPTR=Pop(OPTR); c++; break; case \'>\': // 退栈并将运算结果入栈 theta=OPTR->c;OPTR=Pop(OPTR); b=OPND->f;OPND=Pop(OPND); a=OPND->f;OPND=Pop(OPND); OPND=Push(OPND, Operate(a, theta, b)); break; } //switch } } //while return OPND->f; } //EvaluateExpression //符号生成 char create_symbol(int n) { int n1,j; char symbol[1]; if(n==0) { n1=2; } else if(n=1) { n1=4; } j=random()%n1; if(j==0) symbol[0]=\'+\'; else if(j==1) symbol[0]=\'-\'; else if(j==2) symbol[0]=\'*\'; else symbol[0]=\'/\'; return symbol[0]; } //把数字转换成字符串型 string int_string(int number) { char str[200]; itoa(number,str,10); string str_=str; return str_; } //真分数合成一个字符串 string combination1(string str1,string str2,char k) { string equation; equation=\'(\'+str1+k+str2+\')\'; return equation; } //新生成一个数 string create_num(int proper_fs,int range) { int num,num1,num2,fs; string str_num,str_num1,str_num2; num=random()%range+1; str_num=int_string(num); if(proper_fs==1) { fs=random()%3; if(fs==1)//判断是否生成真分数 { for(;;) { num1=random()%range+1; num2=random()%range+1; if(num1<num2) break; } str_num1=int_string(num1); str_num2=int_string(num2); str_num=combination1(str_num1,str_num2,\'/\'); } } return str_num; } //运算式转换成一个字符串 string combination(string str1,string str2,char k) { string equation; equation=str1+k+str2; return equation; } //得出正确答案 float get_ans(string str) { int len; float ans; len=str.length(); char num[len]; for(int j=0;j<len;j++) { num[j]=str[j]; } //用堆栈解决。。。 ans=EvaluateExpression(num); return ans; } //主函数 int main() { srand((int)time(NULL)); //设置时间种子 ，使得程序每次运行的结果都不同 int num1,num2,num3,num4,count,n,change,amount,shuchu,range,j,repeat=0,bracket,proper_fs; string str_num1,str_num2,temp; float Answer,InputAns; cout<<"有无乘除法？1有，0没有："<<endl; cin>>n; cout<<"是否有括号？1有，0没有："<<endl; cin>>bracket; cout<<"是否有真分数？1有，0没有："<<endl; cin>>proper_fs; cout<<"请输入数字范围："<<endl; cin>>range; cout<<"请输入出题数量："<<endl; cin>>amount; string Equation[amount]; char symbol; cout<<amount<<"道四则运算题如下："<<endl; for(int i=0;i<amount;i++) { count=random()%3+2; str_num1=create_num(proper_fs,range); str_num2=create_num(proper_fs,range); symbol=create_symbol(n); Equation[i]=combination(str_num1,str_num2,symbol); if(count>2) { for(count;count>2;count--) { symbol=create_symbol(n); str_num1=Equation[i]; if(bracket==1) { change=random()%3; if(change==0) { str_num1=\'(\'+str_num1+\')\'; } } symbol=create_symbol(n); str_num2=create_num(proper_fs,range); change=random()%2; if(change==0) { temp=str_num1; str_num1=str_num2; str_num2=temp; } Equation[i]=combination(str_num1,str_num2,symbol); } } //判断是否重复 for(j=0;j<i;j++) { if(Equation[j]==Equation[i]) { i=i-1; repeat=1; break; } } if(repeat!=1)//若不重复，则输出 { cout<<Equation[i]<<"="; //判断结果是否正确 cin>>InputAns; Answer=get_ans(Equation[i]); Answer*=100; int temp=(int)Answer; Answer=((double)temp)/100.00; if(InputAns==Answer) { cout<<"回答正确！"; } else { cout<<"回答错误！正确答案为"; cout<<setprecision(2)<<fixed<<Answer; } cout<<endl; } } }
队友王世强：
http://www.cnblogs.com/wsqJohn/p/5294841.html
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