scopeChecker.c

#include <stdio.h>
#include <stdlib.h>
//Stack.h is a header file that contains a abstract data type stack created to represent a stack, as the own name says
//Stack.h is here among the others gists
#include "Stack.h"
int main(){
	int i;
	Stack p;
	char ex[MAX],aux=0,control=0;
	iniStack(&p);
	printf ("Enter the expression to be evaluated:\n");
	scanf (" %sMAX[^\n]", ex);
	for (i=0;ex[i]!='\0';i++){
		if ((ex[i]=='(') || (ex[i]=='{') || (ex[i]=='[')){
			push(&p,ex[i]);
		}
	}
	for (i=0;ex[i]!='\0';i++){
		if (ex[i]==')'){
			aux=pop(&p);
			if (aux=='(')
				control=1;
			else{
				control=2;
				break;
			}
		} 
		if (ex[i]=='}'){
			aux=pop(&p);
			if (aux=='{')
				control=1;
			else{
				control=2;
				break;
			}
		}
		if (ex[i]==']'){
			aux=pop(&p);
			if (aux=='[')
				control=1;
			else{
				control=2;
				break;
			}
		}
		if (emptyStack(&p)!=1)
			control=2;
			break;
	}
	if (control==1)
		printf ("Valid expression!\n");
	if (control==2)
		printf("Invalid expression!\n");
}