45 lines
1.2 KiB
Java
45 lines
1.2 KiB
Java
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// Longest Palindromic Substring
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import java.util.Scanner;;
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class LongestPalindromicSubstring {
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public static void main(String[] args) {
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Solution s = new Solution();
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String str = "";
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Scanner sc = new Scanner(System.in);
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System.out.print("Enter the string: ");
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str = sc.nextLine();
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System.out.println("Longest substring is : "+s.longestPalindrome(str));
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}
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}
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class Solution {
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public String longestPalindrome(String s) {
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if (s == null || s.length() == 0) {
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return "";
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}
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int n = s.length();
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String maxStr = "";
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for (int i = 0; i < n; ++i) {
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for (int j = i; j < n; ++j) {
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if (isValid(s, i, j) == true) {
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if (j - i + 1 > maxStr.length()) { // update maxStr
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maxStr = s.substring(i, j + 1);
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}
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}
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}
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}
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return maxStr;
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}
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private boolean isValid(String s, int lo, int hi) {
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int n = hi - lo + 1;
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for (int i = 0; i < n / 2; ++i) {
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if (s.charAt(lo + i) != s.charAt(hi - i)) {
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return false;
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}
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}
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return true;
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}
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}
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