jingrui

public class Solution {
    public ArrayList<ArrayList<Integer>> combinationSum(int[] candidates, int target) {
        ArrayList<ArrayList<Integer>> ret = new ArrayList<ArrayList<Integer>>();
        Arrays.sort(candidates);
        ArrayList<Integer> al = new ArrayList<Integer>();
        helper(candidates,target,al,ret,0);
        return ret;
    }
    public void helper(int[] can, int t, ArrayList<Integer> al, ArrayList<ArrayList<Integer>> ret, int i ){
    	if (t == 0){

jingrui

public class Solution {
    public boolean isValidSudoku(char[][] board) {
        // Start typing your Java solution below
        // DO NOT write main() function
        for(int i = 0; i < board.length; i++){
            HashSet hm = new HashSet();
            for(int j = 0; j < board.length; j++){
                if (hm.contains(board[i][j]) && (board[i][j] != '.'))
                    return false;
                hm.add(board[i][j]);

jingrui

public class Solution {
    public int searchInsert(int[] A, int target) {
        // Start typing your Java solution below
        // DO NOT write main() function
        return helper(A,target,0,A.length-1);
    }
    public int helper(int[]a , int t, int s, int e){
        if (e < s)
            return s;
        int m = (s+e)/2;

jingrui

public class Solution {
    public  int[] searchRange(int[] A, int target) {
        int[] ret = new int[2];
        ret[0] = helper(A,target-0.1,0,A.length-1);
        ret[1] = helper(A,target+0.1,0,A.length-1);
        return ret;
    }
    public  int helper(int[] a, double t,int s, int e){
        if (e < s){
          if (s >= a.length)

jingrui

public class Solution {
    public int search(int[] A, int target) {
        // Start typing your Java solution below
        // DO NOT write main() function
        int s = 0; 
        int e = A.length -1;
        return sear(A,target,s,e);
    }
    public int sear(int[] A, int tar, int s, int e){
        if (e < s)

jingrui

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;

public class Solution {

jingrui

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;

public class Solution {

jingrui

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;

public class Solution {

jingrui

1. cmu machine learning online class
http://alex.smola.org/teaching/cmu2013-10-701/index.html

jingrui

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;

public class Solution {