57 lines
1.1 KiB
Java
57 lines
1.1 KiB
Java
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package test;
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import java.io.*;
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import java.util.*;
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/*
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* Algorithm explanation https://leetcode.com/problems/longest-palindromic-substring/
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*/
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public class LongestPalindromicSubstring {
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public static void main(String[] args) {
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String a = "babad";
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String b = "cbbd";
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String aLPS = LPS(a);
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String bLPS = LPS(b);
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System.out.println(a + " => " + aLPS);
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System.out.println(b + " => " + bLPS);
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}
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private static String LPS(String input) {
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if(input == null || input.length() == 0){
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return input;
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}
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boolean arr[][] = new boolean[input.length()][input.length()];
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int start = 0, end = 0;
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for (int g = 0; g < input.length(); g++) {
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for (int i = 0, j = g; j < input.length(); i++, j++) {
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if (g == 0) {
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arr[i][j] = true;
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} else if (g == 1) {
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if (input.charAt(i) == input.charAt(j)) {
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arr[i][j] = true;
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} else {
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arr[i][j] = false;
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}
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} else {
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if (input.charAt(i) == input.charAt(j) && arr[i + 1][j - 1]) {
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arr[i][j] = true;
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} else {
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arr[i][j] = false;
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}
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}
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if (arr[i][j]) {
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start = i;
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end = j;
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}
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}
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}
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return input.substring(start, end + 1);
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}
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}
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