document paranthesis matching

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Krishna Vedala 2020-05-28 11:24:46 -04:00
parent 0c85156573
commit 4206ac2a29
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@ -1,76 +1,75 @@
/**
* @file
* @brief Perform paranthesis matching. \note Do not know the application of
* this, however.
* @note Implementation is C-type and does not utilize the C++ constructs
* @todo implement as a C++ class
*/
#include <iostream> #include <iostream>
#include <string> #ifdef _MSC_VER
#include <string> // Visual Studio C requires this include
using namespace std; #else
#include <cstring>
#endif
/** check number */
#define MAX 100 #define MAX 100
// -------------- stack -------------- //! @{-------------- stack --------------
//! global stack
char stack[MAX]; char stack[MAX];
//! pointer to track stack index
int top = -1; int top = -1;
void push(char ch) //! push byte to stack variable
{ void push(char ch) { stack[++top] = ch; }
stack[++top] = ch;
//! pop a byte out of stack variable
char pop() { return stack[top--]; }
//! @}-------------- end stack -----------
/** return opening paranthesis corresponding to the close paranthesis
* @param[in] ch closed paranthesis character
*/
char opening(char ch) {
switch (ch) {
case '}':
return '{';
case ']':
return '[';
case ')':
return '(';
case '>':
return '<';
}
return '\0';
} }
char pop() int main() {
{ std::string exp;
return stack[top--]; int valid = 1, i = 0;
} std::cout << "Enter The Expression : ";
std::cin >> exp;
// -------------- end stack -----------
while (valid == 1 && i < exp.length()) {
char opening(char ch) if (exp[i] == '(' || exp[i] == '{' || exp[i] == '[' || exp[i] == '<') {
{ push(exp[i]);
switch (ch) } else if (top >= 0 && stack[top] == opening(exp[i])) {
{ pop();
case '}': } else {
return '{'; valid = 0;
case ']': }
return '['; i++;
case ')': }
return '(';
case '>': // makes sure the stack is empty after processsing (above)
return '<'; if (valid == 1 && top == -1) {
} std::cout << "\nCorrect Expression";
} } else {
std::cout << "\nWrong Expression";
int main() }
{
return 0;
string exp;
int valid = 1, i = 0;
cout << "Enter The Expression : ";
cin >> exp;
while (valid == 1 && i < exp.length())
{
if (exp[i] == '(' || exp[i] == '{' || exp[i] == '[' || exp[i] == '<')
{
push(exp[i]);
}
else if (top >= 0 && stack[top] == opening(exp[i]))
{
pop();
}
else
{
valid = 0;
}
i++;
}
// makes sure the stack is empty after processsing (above)
if (valid == 1 && top == -1)
{
cout << "\nCorrect Expression";
}
else
{
cout << "\nWrong Expression";
}
return 0;
} }