使用栈实现判断输入的符号是否匹配

实现的大致原理是将所有左符号添加到栈中，当遇到右符号的时候就和栈顶元素做匹配，如果能匹配这将当前栈顶元素pop掉，从而使栈内始终都是左符号，只是将新输入的右括号与栈顶的做匹配，注意右符号是没有入栈的！/*date: 2014/6/5time: 20:07运行环境：windows 7 + MinGW + Sublime_text_3注意：此代码不能判断符号相互交叉的匹配，比如({)},只能测试{([])({})}类型的*/#include <iostream>#include <string>#include <cstdlib>using namespace std;struct Stack{int size;//stack's max sizechar *base;char *top;};bool init_stack(Stack &s)//初始化栈{char *tmp = new char[100];if (tmp == NULL){cout << "applay for memory failed" << endl;exit(1);}s.base = s.top = tmp;s.size = 100;//最大栈容量return true;}bool push(Stack &s, char ch)//插入元素{if (s.top - s.base > s.size - 1)//检查是否溢出{cout << "ERROR! STACKOVERFLLOW" << endl;return false;}*s.top = ch;//插入入元素s.top++;//栈顶指针上移return true;}bool pop(Stack &s)//删除元素{if (s.base == s.top){return false;}s.top--;//顶端指针下移}char get_top(Stack &s)//获取栈顶元素{if (s.base == s.top){return false;}char *tmp = s.top;//使用tmp表示临时指针，防止栈顶指针被修改tmp--;return *tmp;}bool empty(Stack &s)//判断是否为空栈{if (s.base == s.top)return true;elsereturn false;}//遍历全栈的函数，测试时用，能正常使用时可以不用void traversal(Stack &s){if (s.base == s.top){cout << "empty" << endl;return;}char *tmp = s.top;tmp--;while (tmp >= s.base){cout << *tmp << "";tmp--;}cout << endl;}////////////////////////////////////////////////int main(int argc, char const *argv[]){Stack s;init_stack(s);char str[100];cout << "input a charactor string \"() {} []\"" << endl;cin >> str;for (int i = 0; i < strlen(str); ++i){switch(str[i]){//如果是左括号都将其入栈case '(': push(s, '('); break;case '[': push(s, '[');break;case '{': push(s, '{');break;//如果是右括号，case ')': if (empty(s) || get_top(s) == ')')//判断当前栈是否为空，或者栈顶已经是右括号push(s, ')');//继续入栈else if (get_top(s) == '(') //如果正好前后匹配，则清除栈顶元素pop(s);break;case ']':if (empty(s) || get_top(s) == ']')push(s, ']');else if (get_top(s) == '[')pop(s);break;case '}':if (empty(s) || get_top(s) == '}')push(s, '}');else if (get_top(s) == '{')pop(s);break;default:cout << "what you've input is invalid" << endl;return 1;}}if (s.base == s.top)cout << "congratuate, all charactor has matched" << endl;elsecout << "sorry! \'" << *s.base << "\' can not matched" << endl;//只能输出栈底没有匹配的符号return 0;}/*测试字符串：((({{[[[(({[]}))]]]}})))*/