用标准栈实现括号匹配(自制)

#include "stack.h" bool Legal(char a[]) { SqStack s1; SElemType e; InitStack(&s1); int i=0; while(a[i]!='\0') { switch(a[i]) { case '(': case '[': case '{': Push(&s1,a[i]); break; case ')': if(StackEmpty(&s1)) return false; else { GetTop(&s1,&e); if(e=='(') Pop(&s1,&e); else return false; } break; case ']': if(StackEmpty(&s1)) return false; else { GetTop(&s1,&e); if(e=='[') Pop(&s1,&e); else return false; } break; case '}': if(StackEmpty(&s1)) return false; else { GetTop(&s1,&e); if(e=='{') Pop(&s1,&e); else return false; } break; } i++; }; if(StackEmpty(&s1)) return true; else return false; } void main() { char a[50]; bool b; char yn; char lan; cout<<"Select the language: | 请选择语言："<<endl; cout<<"Chinese(C) | English(E) | 汉语(C) | 英语(E)"<<endl; cin>>lan; switch(lan) { case 'c': case 'C': cout<<"\t\t\t括号匹配"<<endl; label: cout<<"请输入表达式:"; cin>>a; b=Legal(a); if(!b) cout<<"括号匹配错误"<<endl; else cout<<"括号匹配正确"<<endl; cout<<"是否继续?(Y/N):";cin>>yn; if(yn=='Y'||yn=='y') goto label; break; case 'e': case 'E': cout<<"\t\t\tmatching parentheses"<<endl; label1: cout<<"Please input a expression:"; cin>>a; b=Legal(a); if(!b) cout<<"wrong"<<endl; else cout<<"right"<<endl; cout<<"continue?(Y/N):";cin>>yn; if(yn=='Y'||yn=='y') goto label1; } }