雯雯熊孩子

iven an array of n positive integers and a positive integer s, find the minimal length of a subarray of which the sum ≥ s. If there isn't one, return 0 instead. For example, given the array [2,3,

Given an array of integers, find two non-overlapping subarrays which have the largest sum. The number in each subarray should be contiguous. Return the largest sum. Note The subarray shoul

Given a sorted integer array where the range of elements are [lower, upper] inclusive, return its missing ranges. For example, given [0, 1, 3, 50, 75], lower = 0 and upper = 99, return ["2", "4->

Given two integers representing the numerator and denominator of a fraction, return the fraction in string format. If the fractional part is repeating, enclose the repeating part in parentheses.

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times. You may assume that the array is non-empty and the majority element

public int numDistinct(String S, String T) { int row = S.length(); int col = T.length(); int[][] m = new int[row][col]; for (int i = 0; i < row; i++) {

这两天做了3sum, 3sum closest, 4sum 一个模板就是先sort array, 取一个或两个下标（depend on 3sum or 4sum) 然后用另外两个指针指向头和尾。由于数组已经排序，只需要这两个指针扫一遍。 教训：当sum == target时，经常忘记移动两个下标(k, l)，使得死循环或者不再去判断k+1到l-1之间的数组。 public class So

Given an unsorted integer array, find the first missing positive integer. For example, Given [1,2,0] return 3, and [3,4,-1,1] return 2. Your algorithm should run in O(n) time and uses constant

Design an algorithm to find the kth number such that the only prime factors are 3, 5, and 7. The eligible numbers are like 3, 5, 7, 9, 15 ... Example If k=4, return 9. Challenge O(n

Given an integers array A. Define B[i] = A[0] * ... * A[i-1] * A[i+1] * ... * A[n-1], calculate B without divide operation. Example For A=[1, 2, 3], B is [6, 3, 2] public ArrayList produ

Write an efficient algorithm that searches for a value in an m x n matrix, return the occurrence of it. This matrix has the following properties:     * Integers in each row are sorted from left

public int findMin(int[] num) { int left = 0; int right = num.length-1; while (left = num[right]) { int mid = left + (right-left)/2; if (num[mid] == nu

Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). Find the minimum element. You may assume no duplicate exists in

Follow up for "Remove Duplicates": What if duplicates are allowed at most twice? For example, Given sorted array A = [1,1,1,2,2,3], Your function should return length = 5, and A is now [1,1,2,

Given an array of integers, the majority number is the number that occurs more than 1/3 of the size of the array. Find it. Note There is only one majority number in the array Example

Given an array of integers and a number k, the majority number is the number that occurs more than 1/k of the size of the array. Find it. Note There is only one majority number in the array.

Given an integer array, heapify it into a min-heap array. For a heap array A, A[0] is the root of heap, and for each A[i], A[i * 2 + 1] is the left child of A[i] and A[i * 2 + 2] is the right child

Having an input stream of n, select k elements with equal probability. Algorithm:  1. select k elements into the result first 0....k-1 2. for k....n-1 elements, each time i, generate a random n

A peak element is an element that is greater than its neighbors. Given an input array where num[i] ≠ num[i+1], find a peak element and return its index. The array may contain multiple peaks, i

Find K-th largest element in an array. Note You can swap elements in the array Example In array [9,3,2,4,8], the 3th largest element is 4 Challenge O(n) time, O(1) space

Given an array of integers and a number k, find knon-overlapping subarrays which have the largest sum. The number in each subarray should be contiguous. Return the largest sum. Note The su

Given an array and a value, remove all instances of that value in place and return the new length. The order of elements can be changed. It doesn't matter what you leave beyond the new length. 简单题

Rotate an array of n elements to the right by k steps. For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4] public void rotate(int[] nums, int k) {

Given two numbers represented as strings, return multiplication of the numbers as a string. Note: The numbers can be arbitrarily large and are non-negative. public String multiply(String n

Given n items with size A[i] and value V[i], and a backpack with size m. What's the maximum value can you put into the backpack? Note You cannot divide item into small pieces and the total siz

Given an array with integers. Find two non-overlapping subarrays A and B, which|SUM(A) - SUM(B)| is the largest. Return the largest difference. Note The subarray should contain at least on

Given an unsorted array, find the maximum difference between the successive elements in its sorted form. Try to solve it in linear time/space. Return 0 if the array contains less than 2 elements

Given a list of integers, which denote a permutation. Find the previous permutation in ascending order. Note The list may contains duplicate integers. Example For [1,3,2,3], the pre

The API: int read4(char *buf) reads 4 characters at a time from a file. The return value is the actual number of characters read. For example, it returns 3 if there is only 3 characters left in the

Given n unique integers, number k (1 Example Given [1,2,3,4], k=2, target=5, [1,4] and [2,3] are possible solutions. public ArrayList> kSumII(int A[], int k, int target) { Array

Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length. Do not allocate extra space for another array, you must do this in place with

public void nextPermutation(int[] num) { int n = num.length; if (n <= 1) { return; } int cur = n-1; while (cur >= 1 && num[cur-1]>= num[cur]) {

public String getPermutation(int n, int k) { List num = new ArrayList(); for (int i = 0; i < n; i++) { num.add(i+1); } int factorial = 1; for (int i

public int maxPoints(Point[] points) { int max = 1; if (points.length == 0) { return 0; } for (int i = 0; i < points.length-1; i++) { Point curP

http://leetcode.com/oldoj#question_130 Given a 2D board containing 'X' and 'O', capture all regions surrounded by 'X'. A region is captured by flipping all 'O's into 'X's in that surrounded region .

public static List findPrime(int n) { List preResult = new ArrayList(); List result = new ArrayList(); for (int i = 1; i <= n; i++) { preResult.add(i); } int divisorInd = 1; // start fro

There are N children standing in a line. Each child is assigned a rating value. You are giving candies to these children subjected to the following requirements: Each child must have at least on

The gray code is a binary numeral system where two successive values differ in only one bit. Given a non-negative integer n representing the total number of bits in the code, print the sequence of gr

You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). Follow up: Could you do this in-place? 犯错的地方：开始忘了i是从offset开始，以为从0开始 public class Solution {    

1. valid sudoku 就是检测每行，每列，每个block是否有重复数字。 public class Solution {     public boolean isValidSudoku(char[][] board) {         // Start typing your Java solution below         // DO NOT write main() fu