Ray1988

/*
Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Find two lines, which together with x-axis forms a container, such that the container contains the most water.

Note: You may not slant the container.
*/

public class Solution {
    public int maxArea(int[] height) {
     if (height==null || height.length<2){
         return 0;

Ray1988

/*
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 [1,1,2,2,3].
*/

Ray1988

"""
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 [1,1,2,2,3].
"""

Ray1988

"""
Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.

For example,
Given n = 3,

You should return the following matrix:
[
 [ 1, 2, 3 ],
 [ 8, 9, 4 ],

Ray1988

public class Solution {
    public void setZeroes(int[][] matrix) {
        if (matrix==null||matrix.length==0){
            return;
        }
        
        boolean[] rows=new boolean[matrix.length];
        boolean[] cols=new boolean[matrix[0].length];
        
        for (int row=0; row<matrix.length; row++){

Ray1988

# without extra space
class Solution:
    # @param matrix, a list of lists of integers
    # RETURN NOTHING, MODIFY matrix IN PLACE.
    def setZeroes(self, matrix):
        if matrix==None or len(matrix)==0:
             return 
         
        # use first col and row as buffer to hold a flag to check if accordinate col or row should be 0

Ray1988

class Solution:
    # @param A a list of integers
    # @param target an integer
    # @return a boolean
    def search(self, A, target):
        if A==None or len(A)==0:
            return False
        start=0;
        end=len(A)-1
        

Ray1988

class Solution:
    # @return a list of integers
    def getRow(self, rowIndex):
        if rowIndex<0:
            return None
        result=[0]*(rowIndex+1)
        result[0]=1
        
        for i in range(1,len(result)):
            result[i]=1

Ray1988

/*
Given an index k, return the kth row of the Pascal's triangle.

For example, given k = 3,
Return [1,3,3,1].

Note:
Could you optimize your algorithm to use only O(k) extra space?
*/
//6/2014

Ray1988

Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.

For example:
Given the below binary tree and sum = 22,
              5
             / \
            4   8
           /   / \
          11  13  4
         /  \      \