QUESTION

Write a function to generate all possible n pairs of balanced parentheses.\n\nFor example, if n=1\n{}\nfor n=2\n{}{}\n{{}}.

ANSWER

#include <stdio.h>
# include<stdio.h>
# define MAX_SIZE 100
 
void _printParenthesis(int pos, int n, int open, int close);
 
// Wrapper over _printParenthesis()
void printParenthesis(int n)
{
    if(n > 0)
        _printParenthesis(0, n, 0, 0);
    return;
}    
 
void _printParenthesis(int pos, int n, int open, int close)
{
    static char str[MAX_SIZE];   
     
    if(close == n) 
    {
        printf("%s \n", str);
        return;
    }
    else
    {
        if(open > close) 
        {
            str[pos] = '}';
            _printParenthesis(pos+1, n, open, close+1);
        }
         
        if(open < n)
        {
        str[pos] = '{';
        _printParenthesis(pos+1, n, open+1, close);
        }
    }
}
 
// Driver program to test above functions
int main()
{
    int n ;
  scanf("%d",&n);
    printParenthesis(n);
    getchar();
    return 0;
}