148.cpp

// C++ program to remove duplicates, the order of
// characters is not maintained in this progress
#include <bits/stdc++.h>
#define NO_OF_CHAR 256
using namespace std;

int* getcountarray(string str2)
{
	int* count = (int*)calloc(sizeof(int), NO_OF_CHAR);

	for (int i = 0; i < str2.size(); i++)
	{
		count[str2[i]]++;
	}

	return count;
}

/* removeDirtyChars takes two
string as arguments: First
string (str1) is the one from
where function removes dirty
characters. Second string(str2)
is the string which contain
all dirty characters which need
to be removed from first
string */
string removeDirtyChars(string str1, string str2)
{
	// str2 is the string
	// which is to be removed
	int* count = getcountarray(str2);
	string res;
	
	// ip_idx helps to keep
	// track of the first string
	int ip_idx = 0;

	while (ip_idx < str1.size())
	{
		char temp = str1[ip_idx];
		if (count[temp] == 0)
		{
			res.push_back(temp);
		}
		ip_idx++;
	}

	return res;
}

// Driver Code
int main()
{
	string str1 = "geeksforgeeks";
	string str2 = "mask";

	// Function call
	cout << removeDirtyChars(str1, str2) << endl;
}