Given a string str consisting of digits, alphabets, and special characters. The task is to extract all the integers from the given string.
Examples:
Input: str = "neveropen A-118, Sector-136, Uttar Pradesh-201305" Output: 118 136 201305 Input: str = " 1abc35de 99fgh, dd11" Output: 1 35 99 11
Approach 1:
- Replace all the non-digit characters with spaces (” “).
- Now replace every consecutive group of spaces with a single space.
- Eliminate the leading and the trailing spaces (if any) and the final string will only contain the required integers.
Below is the implementation of the above approach:
Java
// Java implementation of the approachpublic class GFG { // Function to return the modified string static String extractInt(String str) { // Replacing every non-digit number // with a space(" ") str = str.replaceAll("[^\\d] & quot;, " "); // Remove extra spaces from the beginning // and the ending of the string str = str.trim(); // Replace all the consecutive white // spaces with a single space str = str.replaceAll(" + ", " "); if (str.equals(" ")) return " -1 & quot; ; return str; } // Driver code public static void main(String[] args) { String str = " avbkjd1122klj4 543 af& quot; ; System.out.print(extractInt(str)); }} |
Output
1122 4 543
Time Complexity: O(n), Here n is the length of the string.
Auxiliary Space: O(1), As constant extra space is used.
Approach 2:
Java
// Java implementation of the approachpublic class GFG { // Function to return the modified string static String extractInt(String str) { // Replacing every non-digit number // with a space(" ") str = str.replaceAll("[^0-9]", " "); // regular expression // Replace all the consecutive white // spaces with a single space str = str.replaceAll(" +", " "); if (str.equals("")) return "-1"; return str; } // Driver code public static void main(String[] args) { String str = "avbkjd1122klj4 543 af"; System.out.print(extractInt(str)); }} |
Output
1122 4 543
Time Complexity: O(n), Here n is the length of the string.
Auxiliary Space: O(1), As constant extra space is used.
