The application of the stack—Parentheses Matching(括弧匹配）

標籤：des   style   blog   color   os   io   for   ar   

The thought of the algorithm is as follows:

(1) Initially set up an empty stack, sequentially read in parentheses;

(2) If it is a right parentheses, or it matches the stack top element, or it is illegal;

(3) If it is a left parentheses, it will be pushed into the stack.

When the algorithm is end, if the stack is empty, the parentheses matching is successful;

if the stack is not empty, the parentheses matching is failing.

The codes are as follows(C++):

 1 #include "stdafx.h" 2 #include<iostream> 3 #include "string.h" 4 using namespace std; 5 #define stacksize 100 6 //定義棧的結構 7 struct stack{ 8     char stackstr[stacksize]; 9     int top;10 };11 //初始化棧12 void InitStack(stack &s){13     s.top = -1;14 }15 //入棧操作16 void Push(stack &s, char ch){17     if (s.top == stacksize - 1)18         cout << "站已滿" << endl;19     else{20         s.top++;21         s.stackstr[s.top] = ch;22     }23 }24 //出棧操作25 char Pop(stack &s){26     if (s.top == -1)27         return 0;28     else{29         char ch = s.stackstr[s.top];30         return ch;31     }32 }33 //判斷棧是否為空白34 int IsEmpty(stack &s){35     if (s.top == -1)36         return 0;37     else38         return 1;39 }40 //括弧匹配41 int PrintMatchedPairs(char *str){42     stack s;43     InitStack(s);44     int strLen = strlen(str);45     for (int i = 0; i < strLen; i++){46         char ch = str[i];47         switch(ch){48         case ‘(‘:49         case ‘[‘:50         case ‘{‘:51             Push(s, ch);52             break;53         case ‘)‘:54             if (Pop(s) != ‘(‘)55                 return 0;56             break;57         case ‘]‘:58             if (Pop(s) != ‘[‘)59                 return 0;60             break;61         case ‘}‘:62             if (Pop(s) != ‘{‘)63                 return 0;64             break;65         }66     }67     int re = 0;68     re = IsEmpty(s);69     if (re == 0)70         return 0;71     if (re == 1)72         return 1;73 }74 int main(){75     char str[100];76     cout << "請輸入一個括弧的字串：" << endl;77     cin >> str;78     int re=PrintMatchedPairs(str);79     if (re == 0)80         cout << "括弧完全符合" << endl;81     else82         cout << "括弧不匹配"<<endl;83     return 0;84 }