C program to balance parentheses

C program to balance parentheses

Output:

Enter the expression:
( ( ( a + b ) ( ( c + d ) ) )

The resultant expression is:     (  (  a + b ) (  (  c + d ) ) )

Implementation:

#include <stdio.h> #include <stdlib.h> #include <string.h> #define MAX 100 int main(void) { char *s; int l,r,i,n; int hash[MAX]; s=(char*)malloc(sizeof(char)*MAX); printf("Enter the expression:\n"); scanf("%s",s); memset(hash,0,sizeof(hash)); l=0; n=strlen(s); while(*(s+l)!='(') { //hash[l]=1; l++; } r=l+1; while(*(s+r)) { if(*(s+r)==')' || hash[r]==0) { l=r; while(*(s+l)!='(' && hash[l]!=1) { l--; } hash[l]=1; hash[r]=1; /* while(*(s+l)!='(') l++; while(*(s+r)!=')') r++; */ } r++; } /*for(i=0;i<n;i++) printf("%d ",hash[i]);*/ printf("\n"); printf("The resultant expression is: "); for(i=0;i<n;i++) { if(hash[i]==1) printf("%c ",*(s+i)); else if(*(s+i)!='(' && *(s+i)!=')') printf("%c ",*(s+i)); else printf(" "); } return 0; }