Write a C program that takes two strings as arguments and removes the characters from first string which are present in second string called mask string.
ex: str1 “crazy for code”
str2 “cod”
Result: “razy e”
Steps:
1) Get count array from mask string which stores count of chars from mask string.
2) Check for input string if it contains chars from count array with frequency > 0 then skip else copy that char in input string.
3) In the end, copy ‘\o’
int *getMaskStrCount(char *str)
{
int *count = (int *)malloc(sizeof(int)*256);
int i;
for (i = 0; *(str+i); i++)
count[*(str+i)]++;
return count;
}
char *removeMaskStr(char *str, char *mask_str)
{
int *count = getMaskStrCount(mask_str);
int i = 0, j = 0;
char temp;
while(*(str + i))
{
if(count[*(str + i)] == 0)
{
*(str + j) = *(str + i);
j++;
}
i++;
}
*(str+j) = '\0';
return str;
}
Time Complexity: O(m+n) Where m is the length of mask string and n is the length of the input string.
public class CorrectQuestion {
public static void main(String[] args) {
String s1=”crazy for code” ;
String s2=”cod”;
char [] arr=new char[256];
System.out.println();
for(int i=0;i<s2.length();i++)
{
arr[s2.charAt(i)]++;
}
String Str =" ";
for(int i=0;i<s1.length();i++)
{
if(arr[s1.charAt(i)] == 0)
{
Str+=s1.charAt(i);
}
}
System.out.println(Str.trim());
}
}
package com.string;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Set;
public class RemoveCharacterFromFisrtStringWhichPInSecondString {
public static void removeCharactersFromFirstString(String str1,String str2){
StringBuilder sb = new StringBuilder(str1.toLowerCase());
char maskArray[] = populateMaskArray(str2);
for(int i=0;i<str1.length();i++){
char ch = str1.toLowerCase().charAt(i);
int index = sb.toString().indexOf(ch);
if(maskArray[ch] == ch) {
sb.deleteCharAt(index);
}
}
System.out.println(sb.toString());
}
/**
* Time Complexity: O(m) Where m is the length of mask string.
*/
static char[] populateMaskArray(String mask) {
char[] array = new char[256];
for(int i = 0; i < mask.length(); i++) {
array[mask.charAt(i)] = mask.charAt(i);
}
return array;
}
public static void main(String[] args) {
String str1 = "India is country";
String str2 = "in";
removeCharactersFromFirstString(str1,str2);
}
}