58 lines
2.3 KiB
Java
58 lines
2.3 KiB
Java
package OOP.Java.lab_3;
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public class lab_3 {
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static int maxStrLength;
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static String result;
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public static void cSubUtil(StringBuilder stringbuilder, int leftBoundary, int rightBoundary) {
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String string = stringbuilder.toString().toLowerCase().replaceAll("[^a-z]","");
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// check if the indices lie in the range of string
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// and also if it is palindrome
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while (leftBoundary >= 0 && rightBoundary < string.length() && string.toLowerCase().charAt(leftBoundary) == string.toLowerCase().charAt(rightBoundary)) {
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// expand the boundary
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leftBoundary--;
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rightBoundary++;
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}
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// if it's length is greater than maxStrLength update
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// maxLength and result
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if (rightBoundary - leftBoundary - 1 >= maxStrLength) {
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result = string.substring(leftBoundary + 1, rightBoundary);
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maxStrLength = rightBoundary - leftBoundary - 1;
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}
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}
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public static int longestPalSubstr(StringBuilder string)
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{
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result = "";
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maxStrLength = 1;
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// for every index in the string check palindromes
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// starting from that index
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for (int i = 0; i < string.length(); i++) {
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// check for odd length palindromes
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cSubUtil(string, i, i);
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// check for even length palindromes
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cSubUtil(string, i, i + 1);
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}
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System.out.println("Longest palindrome substring is: " + compareStrings(string));
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return compareStrings(string).length();
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}
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public static String compareStrings(StringBuilder builder) {
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for (int leftBoundary = 0; leftBoundary <= builder.length(); leftBoundary++) {
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for (int rightBoundary = builder.length(); rightBoundary >= leftBoundary; rightBoundary--) {
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if (result.equals(builder.substring(leftBoundary, rightBoundary).toLowerCase().replaceAll("[^a-z]",""))) {
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return builder.substring(leftBoundary, rightBoundary);
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}
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}
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}
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return "";
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}
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public static void main(String[] args) {
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StringBuilder stringToDetect = new StringBuilder("Eva, can I see bees in a cave?");
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System.out.println("Initial string: " + stringToDetect);
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System.out.println("Length is: " + longestPalSubstr(stringToDetect));
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}
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}
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