// match parentheses#include <iostream.h>#include <string.h>#include <stdio.h>#include "stack.h"const int MaxLength = 100; // max expression lengthvoid PrintMatchedPairs(char *expr){// Parenthesis matching.   Stack<int> s(MaxLength);   int j, length = strlen(expr);   // scan expression expr for ( and )   for (int i = 1; i <= length; i++) {      if (expr[i - 1] == '(') s.Add(i);      else if (expr[i - 1] == ')')   	try {s.Delete(j);  // unstack match             cout << j << ' ' << i << endl;}        catch (OutOfBounds)             {cout << "No match for right parenthesis"                   << " at " << i << endl;}      }   // remaining ( in stack are unmatched   while (!s.IsEmpty()) {      s.Delete(j);      cout << "No match for left parenthesis at "           << j << endl;}}void main(void){   char expr[MaxLength];   cout << "Type an expression of length at most "        << MaxLength << endl;   cin.getline(expr, MaxLength);   cout <<"The pairs of matching parentheses in"        << endl;   puts(expr);   cout <<"are" << endl;   PrintMatchedPairs(expr);}