此函数验证式子是否正确

1、#include<iostream> #include<string> #include<stack> #include"Tree.h" /Checks if expression if ok/ bool isok(string exp) /此函数验证式子是否正确，即是否符合运算规则。 char check; int error=0; int lb=0; int rb=0; if(exp.size()=1)return false; else if(IsOperator(exp0)|IsOperator(expexp.size()-1)&

2、amp;&exp0!='('&&expexp.size()-1!=')') /此处若不加，在遇到某些式子时，会出现非法操作。 return false; for(int m=0;m<exp.size();m+) check=expm; if(IsOperand(check); /如果是数字，跳过，不管。 else if(IsOperator(check) if(check=')') rb+; if(IsOperator(expm+1)&&(expm+1='+'|expm+1='

3、-'|expm+1='*'|expm+1='/'|expm+1=''|expm+1=')') m+; if(expm=')') rb+; else if(IsOperator(expm+1) error+; else if(check='(') lb+; if(expm+1='(') m+; lb+; else if(IsOperator(expm+1) error+; else if(IsOperator(expm+1)&&expm+1='('

4、;) m+; lb+; else if(IsOperator(expm+1) error+; else error+; if(error=0&&lb=rb) return(true); else return(false); / int main() /主函数开始 binary_tree etree; stack<binary_tree>NodeStack; stack<char>OpStack; string infix; char choice='y' char c; while(choice='y'|choice=&

5、#39;Y') cout<<"nn请输入表达式，不要带空格;n" cin>>infix; cout<<"-"<<'n' cout<<"表达式为: "<<infix<<'n' if(isok(infix) for(int i=0;i<infix.size();i+) c=infixi; if(IsOperand(c) string tempstring; tempstring=tempstring+c; wh

6、ile(i+1<infix.size()&&IsOperand(infixi+1) tempstring=tempstring+infix+i; binary_tree temp; temp.root=build_node(tempstring); NodeStack.push(temp); / else if(c='+'|c='-'|c='*'|c='/'|c='') if(OpStack.empty() OpStack.push(c); else if(OpStack.top()='

7、;(') OpStack.push(c); else if(TakesPrecedence(c,OpStack.top() OpStack.push(c); else while(!OpStack.empty()&&(TakesPrecedence(OpStack.top(),c)|addition(OpStack.top(),c) binary_tree temp_tree; string thisstring="" thisstring=thisstring+OpStack.top(); OpStack.pop(); etree.root=bui

8、ld_node(thisstring); copy(temp_tree.root,NodeStack.top().root); NodeStack.pop(); etree.root->right_child=temp_tree.root; temp_tree.root=NULL; copy(temp_tree.root,NodeStack.top().root); etree.root->left_child=temp_tree.root; NodeStack.pop(); temp_tree.root=NULL; copy(temp_tree.root,etree.root);

9、 NodeStack.push(temp_tree); etree.root=NULL; OpStack.push(c); else if(c='(') OpStack.push(c); else if(c=')') while(OpStack.top()!='(') binary_tree temp_tree; string thisstring="" thisstring=thisstring+OpStack.top(); OpStack.pop(); etree.root=build_node(thisstring);

10、copy(temp_tree.root,NodeStack.top().root); NodeStack.pop(); etree.root->right_child=temp_tree.root; temp_tree.root=NULL; copy(temp_tree.root,NodeStack.top().root); etree.root->left_child=temp_tree.root; NodeStack.pop(); temp_tree.root=NULL; copy(temp_tree.root,etree.root); NodeStack.push(temp_

11、tree); etree.root=NULL; OpStack.pop(); / while(!OpStack.empty() binary_tree temp_tree; string thisstring="" thisstring=thisstring+OpStack.top(); OpStack.pop(); etree.root=build_node(thisstring); copy(temp_tree.root,NodeStack.top().root); NodeStack.pop(); etree.root->right_child=temp_tre

12、e.root; temp_tree.root=NULL; copy(temp_tree.root,NodeStack.top().root); etree.root->left_child=temp_tree.root; NodeStack.pop(); temp_tree.root=NULL; copy(temp_tree.root,etree.root); NodeStack.push(temp_tree); if(!OpStack.empty() etree.root=NULL; cout<<"打印结点如下: " etree.print(); bin

13、ary_tree temp; copy(temp.root,etree.root); cout<<'n' cout<<"结点个数为："<<etree.counter()<<'n' cout<<"以下是，中间的计算结果："<<'n' etree.evaluate(); cout<<'n' cout<<"结果是: " cout<<etree.root->data&

14、lt;<'n' cout<<"-"<<'n' cout<<"是不是要进行二叉树排序，并显示？若是升序点A，若是降序点B,若不是点C。"<<'n' char c1; cin>>c1; if(c1='A'|c1='a') binary_tree temp1; copy(temp1.root,temp.order().root); /此处代码无需再改 temp1.inprint(temp1.root);/前边程序有错,此处TEMP1为空.所以没有输出. else if(c1='B'|c1='b') binary_tree temp1; copy(temp1.root,temp.order().root); temp1.deprint(temp1.root); cout<<"nnRun Program again?Enter<y/n>:" cin>>choice; else cout<<&quo