This repository manages source I used to practice the algorithms on LeetCode with Java.
All the problems belong to LeetCode.
https://leetcode.com/
Besides, not all the solutions are my original works.
I did consult lots of resource on the internet.
Mac OS X

write down the solution with the class Solution, and then name the file with the # of the problem.

ex. file name like 1.java which contents the solution of problem 1.

package sols;
import java.util.*;

public class Solution {
  public int[] twoSum(int[] nums, int target) {
    int[] res = {-1, -1};
    Map<Integer, Integer> map = new HashMap<Integer, Integer>();
    for (int i = 0; i < nums.length; i++) {
      if (map.containsKey(target - nums[i])) {
        res[0] = map.get(target - nums[i]);
        res[1] = i + 1;
        break;
      } else {
        map.put(nums[i], i + 1);
      }
    }
    return res;
  }
}

put the file into "currentdir/src/sols/"

write down the main procedure with the class, and then name the file with the # of the problem.

ex. file name like 1.java

package main;
//Import the required classes of LeetCode;
import objs.*;
import utils.*;
import utils.inputparser;
import sols.Solution;

//Import the required libraries;
import java.io.*;
import java.util.*;

public class Main {
  public static void main(String[] args) throws IOException {
    // create integer parser
    ParserFactory<IntegerParser> factory = new ParserFactory<IntegerParser>(IntegerParser.class);
    IParser<Integer, int[]> intparser = factory.create(args[0]);
    // create solution object
    Solution sol = new Solution();
    // get input file's contents
    ArrayList<int[]> inputList = intparser.parseDataAsList();
    for (int i = 0; i < inputList.size()/2; i++) {
      int[] nums = inputList.get(2*i);
      int target = inputList.get(2*i + 1)[0];
      int[] res = sol.twoSum(nums, target);
      System.out.println(Arrays.toString(res));
    }
  }
}

put the file into "currentdir/src/main/"

InputParser class receives String variable which contents the path of input files to create the object.

parseDataAsSingleValue() return ArrayList<S>
parserDataAsList() return ArrayList<T>
parserDataAsLists() return ArrayList<ArrayList<T>>

where S is Integer for integer parser, Double for double parser and String for string parser. and T is int[] for integer parser, double[] for double parser and String[] for string parser.

Integer Parser

// create integer parser
ParserFactory<IntegerParser> factory = new ParserFactory<IntegerParser>(IntegerParser.class);
IParser<Integer, int[]> intParser = factory.create(args[0]);

Double Parser

// create integer parser
ParserFactory<DoubleParser> factory = new ParserFactory<DoubleParser>(DoubleParser.class);
IParser<Double, double[]> doubleParser = factory.create(args[0]);

String Parser

// create integer parser
ParserFactory<IntegerParser> factory = new ParserFactory<IntegerParser>(IntegerParser.class);
IParser<Integer, int[]> stringParser = factory.create(args[0]);

where args[0] is the path of input file which is defined in test.sh

InputCleaner class is used in InputParser. The program will be stopped and the inappropriate contents will be shown when it is detected.
The follows are the check points:

1. Integer. (1, 2, 34, -4, -62, ...)
2. Integer list. ([1, 2, 34, -4], [34, -4, -62], [0, 3, 19], ...)
3. The List of the Integer lists. ([[1, 2, 34, -4], [34, -4, -62], [0, 3, 19]], ...)
4. double Float. (1.2, 32.2, 0.9, -5.2, -12.2, ...)
5. double Float list. ([1.2, 32.2, 0.9], [0.9, -5.2, -12.2], [0.0, 2.98, -84.234], ...)
6. The List of the double Float lists. ([[1.2, 32.2, 0.9], [0.9, -5.2, -12.2], [0.0, 2.98, -84.234]], ...)

1. Integer or double Float is valided for the check of the list and the list of the lists.
2. [] is valided for the check of the list.
3. [], [[]] are valided for the check of the list of the lists.

write down your input contents in the txt file as the test cases, and name the file with the # of problem.
one input (one arguement) one line.

Solution.sol1(int a)
Solution.sol2(int a, int b)

For sol1, one line per test case. And two lines per testcase for sol2.

For example, the following input contents are used as 1 testcase for Solution.sol(int[] nums, int target)

[2, 7, 11, 15]
9

single int:

1  
-2  
3

int list:

[1,3,4]

int list of the lists:

[[1,2,3],[4,5,6],[7,8,9]]

single double float:

1.3  
-0.2  
3.45

double float list:

[1.2,0.31,4.28]

double float list of the lists:

[[1.2,0.2,3.4],[5.4,5.02,8.46],[0.27,8.88,9.13]]

String:

"string"

string list:

["string1","string2","string3"]

To create the listNode, use int array as input.

[1,3,4]

To create the binary tree, use String as input. Use # for the null node.

[1,2,#,4,5]

argument (optional) # of problem

ex. >./test.sh 1 will run the problem 1 and show the output.

ex. >./test.sh or >./test.sh all will run all the problems and show the results