wushbin’s gists

wushbin / basic-calculator.java

Created February 16, 2020 02:18

https://leetcode.com/problems/basic-calculator/

	/**
	Solution One: Recursion Solution
	**/
	class Solution {
	public int calculate(String s) {
	return cal(s, new int[]{0});
	}

	private int cal(String s, int[] p) {
	int res = 0;

wushbin / integer-to-english-words.java

Created February 16, 2020 02:22

https://leetcode.com/problems/integer-to-english-words

	class Solution {
	String[] ones = {"", "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine"};
	String[] teens = {"Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen",
	"Sixteen", "Seventeen", "Eighteen", "Nineteen"};
	String[] tens = {"", "Ten", "Twenty", "Thirty", "Forty", "Fifty", "Sixty",
	"Seventy", "Eighty", "Ninety"};

	String[] ks = {"", "Thousand", "Million", "Billion"};
	public String numberToWords(int num) {
	if (num == 0) {

wushbin / number-of-atoms.java

Created February 16, 2020 02:24

https://leetcode.com/problems/number-of-atoms/

	/**
	Recursion Solution
	**/
	class Solution {
	public String countOfAtoms(String formula) {
	if (formula == null \|\| formula.length() == 0) {
	return "";
	}
	int len = formula.length();
	Map<String, Integer> res = parse(formula, new int[]{len - 1});

wushbin / solve-the-equation.java

Created February 16, 2020 02:26

https://leetcode.com/problems/solve-the-equation/

	class Solution {
	public String solveEquation(String equation) {
	String[] tokens = equation.split("=");
	if (tokens.length != 2) {
	return "No solution";
	}
	int[] left = parse(tokens[0]);
	int[] right = parse(tokens[1]);

	// move x to left, num to right

wushbin / valid-number.java

Created February 16, 2020 02:27

https://leetcode.com/problems/valid-number/

	class Solution {
	public boolean isNumber(String s) {
	int idx = 0;
	boolean seenE = false;
	boolean seenDot = false;
	boolean seenSign = false;
	boolean seenNum = false;
	s = s.trim();

	while(idx < s.length()) {

wushbin / median-of-two-sorted-arrays.java

Created February 20, 2020 08:56

https://leetcode.com/problems/median-of-two-sorted-arrays

	class Solution {
	public double findMedianSortedArrays(int[] nums1, int[] nums2) {
	// search range solution
	int len = nums1.length + nums2.length;
	double mid = -1;
	if (len % 2 == 1) {
	mid = findKth(nums1, nums2, (len + 1) /2 );
	} else {
	int mid1 = findKth(nums1, nums2, len / 2);
	int mid2 = findKth(nums1, nums2, len / 2 + 1);

wushbin / divide-two-integers.java

Created February 23, 2020 22:09

https://leetcode.com/problems/divide-two-integers/

	/**

	**/

	class Solution {
	public int divide(int dividend, int divisor) {
	if (dividend == Integer.MIN_VALUE && divisor == -1) {
	return Integer.MAX_VALUE;
	}
	if (divisor == 1) {

wushbin / find-first-and-last-position-of-element-in-sorted-array.java

Created February 23, 2020 22:10

	class Solution {
	public int[] searchRange(int[] nums, int target) {
	if (nums == null \|\| nums.length == 0) {
	return new int[]{-1, -1};
	}
	int l = findFirst(nums, target);
	int r = findLast(nums, target);

	return new int[]{l, r};
	}

wushbin / find-minimum-in-rotated-sorted-array.java

Created February 23, 2020 22:14

wushbin / find-peak-element.java

Created February 23, 2020 22:17

https://leetcode.com/problems/find-peak-element/

	class Solution {
	public int findPeakElement(int[] nums) {
	int l = 0;
	int r = nums.length - 1;

	while(l < r) {
	int mid = l + (r - l) / 2;
	int next = mid + 1; // safe to use mid + 1
	if (nums[mid] < nums[next]) {
	l = mid + 1;

Shengbin Wu wushbin