using System;
using System.Collections.Generic;
using System.Text;
namespace LeetCode2019
{
public static class Basic
{
public static void BasicDataStructure()
{
//Primitive data types
bool myBool = true;
byte myByte = 101; // 0 - 255
sbyte mySbyte = 1; // -128 to 127
char myChar = 'a'; //U+0000 to U+FFFF
decimal myDecimal = 300.5m; //±1.0 x 10(-28) to ±7.9228 x 10(+28)
double myDouble = 33.4d;
float myFloat = 33.44f;
int myInt = -5;
uint myUInt = 5;
long myLong = 1000000000000;
ulong myULong = 1000000;
object myObject = new object();
short myShort = 255; //-32,768 to 32,767 Signed 16-bit integer
ushort myUShort = 32776; //0 to 65,535 Unsigned 16-bit integer
string myString = "abc";
//Array :https://www.geeksforgeeks.org/c-sharp-arrays/
//Syntax:
//[] = new [size];
int[] intArray1 = new int[5]; //default value is 0
int[] intArray2 = new int[5] { 1, 2, 3, 4, 5 };
int[] intArray3 = { 1, 2, 3, 4, 5 };
for (int i = 0; i < intArray1.Length; i++)
{
Console.WriteLine(intArray1[i]);
}
//Multidimensional Arrays, (Rectangular Array)
int[,] intArray2D = new int[4, 2]; //two dimensional array
int[,,] intArray3D = new int[4, 2, 3]; // three dimensional array
int rows = intArray3D.GetLength(0);
int cols = intArray3D.GetLength(1);
int heights = intArray3D.GetLength(2);
for (int i = 0; i < rows; i++)
{
for (int j = 0; j < cols; j++)
{
for (int k = 0; k < heights; k++)
{
Console.WriteLine(intArray3D[i, j, k]);
}
}
}
//Jagged Array: array of arrays.
//Jagged array elements maybe of different dimensions and sizes.
int[][] arr = new int[2][];
arr[0] = new int[5] { 1, 2, 3, 4, 5 };
arr[1] = new int[4] { 1, 2, 3, 4 };
for (int i = 0; i < arr.Length; i++)
{
Console.WriteLine("Element [" + i + "] Array: ");
for (int j = 0; j < arr[i].Length; j++)
{
Console.WriteLine("arr[i][j]: " + arr[i][j]);
}
}
//Mix jagged and multidimensional arrays
int[][,] arrMix = new int[3][,]
{ new int [,] {{1, 3 }, {5,7 }},
new int [,] {{ 0, 2}, { 4, 6}, { 8, 9}},
new int [,] {{10, 11 }, {12, 13 }, {13, 14}, { 15, 16}}
};
for (int k = 0; k < arrMix.Length; k++)
{
Console.WriteLine("array[k]: " + k);
for (int i = 0; i < arrMix[k].GetLength(0); i++)
{
for (int j = 0; j < arrMix[k].GetLength(1); j++)
{
Console.Write(arrMix[k][i, j] + " ");
}
}
}
//Arrays are most useful for creating and working with a fixed number of strongly-typed objects.
//Collections provide a more flexible way to work with groups of objects.
//Unlike the arrays, the group of objects you work with
// can grow and shrink dynamically as the needs of the application change.
}
///
/// The basic collection includes the followings:
/// List
/// Dictionary
/// HashSet
/// Stack
/// Queue
///
public static void BasicCollecions()
{
//string
string s = "";
//StringBuilder
///List Add/Remove at the beginning: O(n)
///Add/Remove items at the end: O(1)
///Search for an item(IndexOf, Contains, Find): O(n)
//create a new list
List list = new List();
//Create a list with initial size
var list2 = new List(1000000);
//Some operations on List
//Add an item at the end of the list;
list.Add(5);
//Add the item at index 0
list.Insert(4, 0);
//Remove an item
list.Remove(5);
//remove the item at index 1
list.RemoveAt(1);
//Get the item at 0
var item = list[0];
//return the index of an item
var index = list.IndexOf(4);
//check to see if the list contains an item
var contains = list.Contains(4);
//Return the number of the list
var count = list.Count;
//Iterate over all objects in a list
foreach (var t in list)
{
Console.WriteLine(t);
}
//Dictionary
//Dictionary is useful when you need fast lookups by keys. O(1)
Dictionary dic = new Dictionary();
dic.Add(1, "abc");
dic.Add(2, "bcd");
var dic2 = new Dictionary
{
{1, "abc"},
{2, "bcd"}
};
//Get the value from the key
string value = dic[1];
//Remove an object by its key
dic.Remove(1);
//Remove all objects
dic.Clear();
//Get the number of elements in dictionary
int countDic = dic.Count;
bool containsKey = dic.ContainsKey(1);
bool containsValue = dic.ContainsValue("abc");
foreach (var key in dic.Keys)
{
Console.WriteLine(key);
}
foreach (var val in dic.Values)
{
Console.WriteLine(val);
}
foreach (var keyvaluepair in dic)
{
Console.WriteLine("Key: {0} Value: {1}", keyvaluepair.Key, keyvaluepair.Value);
}
//HashSet: a hash-based collection.
//hashset represents a set of unique items, just like a mathematical set.
//A set cann't contain duplicate and the order of items is not relevant.
//{1,2, 3} is the same as {3,2 1}
var hashSet = new HashSet();
var hashSet2 = new HashSet() { 1, 2, 3 };
//add an object to the set
hashSet.Add(1);
//Remove the object
hashSet.Remove(1);
//Remove all objects
hashSet.Clear();
//check to see if the set contains an object
bool containsObj = hashSet.Contains(1);
//Return the number of objects in the set
int countSet = hashSet.Count;
//Stack
Stack stack = new Stack();
//push items in a stack
stack.Push("https://google.com");
//Check whether has the value
bool hasValue = stack.Contains("google.com");
//Remove and return the item on the top of the stack
var topItem = stack.Pop();
//Return the item on the top of hte stack without removing it
var topExist = stack.Peek();
//Get the total number of the items in stack
int countStack = stack.Count;
//remove all items from stack
stack.Clear();
//Queue
Queue queue = new Queue();
queue.Enqueue(1);
queue.Enqueue(2);
int countQueue = queue.Count;
bool containsVal = queue.Contains(1);
int itemqueue = queue.Dequeue();
int itemQ = queue.Peek();
queue.Clear();
}
}
}
