Remove “b” and “ac” from a given string

PROBLEM :

Given a string, eliminate all “b” and “ac” in the string, replace them in-place and iterate over the string once.

Input:
The first line of input contains an integer T denoting the number of test cases. The description of T test cases follows.
Each test case contains a string of length N.

Output:
Print the resultant substring after removing 'b' and 'ac' from string.

Constraints:
1 = T = 200
1 = N = 200

Example:
Input:
2
acbac
aababc

Output:

aaac
     
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SIMPLE c++ IMPLEMENTATION :
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#include<iostream>
using namespace std;
#include<string.h>
#include<malloc.h>
char* Remove_b_ac(char*) ;
int main()
{
int t ;
char *str;
str=(char*)malloc(100*sizeof(char)) ;
cin>>t ;
while(t--)
{
   cin>>str ;

   str=Remove_b_ac(str) ;
   cout<<str<<endl ;
}
return 0;
}

char* Remove_b_ac(char *str)
{
    int l,i,j ;
    l=strlen(str) ;
    char *strn ;
    strn=(char*)malloc(100*sizeof(char)) ;
    j=0 ;
   
    for(i=0;i<l;i++)
    {
        if(str[i]=='b')
            continue ;
        if(str[i]=='a'&&str[i+1]=='c')
        {
            i++ ;
            continue ;
        }
       
        strn[j]=str[i] ;
        j++ ;
    }
   
    strn[j]='\0' ;
    return strn ;
}

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