BiruLyu’s gists

BiruLyu / 841. Keys and Rooms(#1 ).java

Last active May 29, 2018 01:25

#BFS

	class Solution {
	int count = 0;
	int N = 0;
	public boolean canVisitAllRooms(List<List<Integer>> rooms) {
	if (rooms == null \|\| rooms.size() < 1) return true;
	int n = rooms.size();
	count = n;
	N = n;
	boolean[] visited = new boolean[n];
	Set<Integer> canReach = new HashSet<>();

BiruLyu / 842. Split Array into Fibonacci Sequence(#1 ).java

Created May 27, 2018 03:49

	class Solution {
	public List<Integer> splitIntoFibonacci(String S) {
	List<Integer> res = new ArrayList<>();
	int len = S.length();
	for (int i = 1; i < len && i < 11; i++) {
	if (S.charAt(0) == '0' && i > 1) return res;
	for (int j = 1; j < len - i && j < 11; j++) {
	if (S.charAt(i) == '0' && j > 1) continue;
	long a = Long.valueOf(S.substring(0, i));
	long b = Long.valueOf(S.substring(i, i + j));

BiruLyu / 840. Magic Squares In Grid(#1 ).java

Created May 27, 2018 03:42

	class Solution {
	public int numMagicSquaresInside(int[][] grid) {
	if (grid == null \|\| grid.length < 3 \|\| grid[0].length < 3) return 0;

	int m = grid.length, n = grid[0].length;
	boolean[] visited = new boolean[9];
	int[] rows = new int[3];
	int[] cols = new int[3];
	int[] diags = new int[2];
	boolean flag = false;

BiruLyu / 843. Guess the Word(#1 ).java

Created May 27, 2018 03:40

	/**
	* // This is the Master's API interface.
	* // You should not implement it, or speculate about its implementation
	* interface Master {
	* public int guess(String word) {}
	* }
	*/
	class Solution {
	private int match(String guess, String w) {
	int match = 0;

BiruLyu / 832. Flipping an Image(#1 ).java

Created May 26, 2018 21:12

	class Solution {
	public int[][] flipAndInvertImage(int[][] A) {
	if (A == null \|\| A.length < 1 \|\| A[0].length < 1) return A;
	int m = A.length, n = A[0].length;

	for (int i = 0; i < m; i++) {
	for (int j = 0; j < n / 2; j++) {
	int temp = A[i][j];
	A[i][j] = A[i][n - 1 - j] ^ 1;
	A[i][n - 1 - j] = temp ^ 1;

BiruLyu / 647. Palindromic Substrings(#1 ).java

Created May 26, 2018 06:34

	class Solution {
	public int countSubstrings(String s) {
	if (s == null \|\| s.length() < 0) return 0;
	int count = 0, len = s.length();
	boolean[][] isPalindrome = new boolean[len][len];
	for (int i = len - 1; i >= 0; i--) {
	for (int j = i; j < len; j++) {
	if (s.charAt(i) == s.charAt(j) && (j - i < 2 \|\| isPalindrome[i + 1][j - 1])) {
	isPalindrome[i][j] = true;
	count++;

BiruLyu / 830. Positions of Large Groups(#1 ).java

Created May 8, 2018 21:33

	class Solution {
	public List<List<Integer>> largeGroupPositions(String S) {
	List<List<Integer>> res = new ArrayList<>();
	int len = S.length();
	if (len < 3) return res;
	int start = 0, end = 1;
	while (end < len) {
	while (end < len && S.charAt(end) == S.charAt(end - 1)) {
	end++;
	}

BiruLyu / 831. Masking Personal Information(#1 ).java

Created May 8, 2018 21:31

	class Solution {
	public String maskPII(String S) {
	StringBuilder res = new StringBuilder();
	int idx = S.indexOf('@');
	int len = S.length();
	if (idx > 0) {
	res.append(Character.toLowerCase(S.charAt(0)));
	res.append("*****");
	res.append(S.substring(idx - 1).toLowerCase());
	} else {

BiruLyu / 828. Unique Letter String(#1 ).java

Created May 8, 2018 21:24

	class Solution {
	public int uniqueLetterString(String S) {
	char[] s = S.toCharArray();
	int n = s.length;
	int mod = 1000000007;
	long ret = 0;
	for(int i = 0;i < s.length;i++){
	int l = i-1;
	for(;l >= 0 && s[l] != s[i];l--);
	int r = i+1;

BiruLyu / 140. Word Break II(#1 ).java

Created May 8, 2018 21:22

	public class Solution {
	public List<String> wordBreak(String s, List<String> wordDict) {
	List<String> res = new ArrayList<String>();
	if (s == null \|\| s.length() == 0) {
	return res;
	}
	int max = 0;
	for (String str : wordDict) {
	max = Math.max(str.length(), max);
	}