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.gitignore

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+/.vscode
+/**/practice
+**.exe

Learn-CPP/Day-01/hello.cpp

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+// Let's with the basics of CPP
+
+// Import a library 😁
+
+#include <iostream>   // It's precompiled code, which includes keywords, namespaces
+
+using namespace std;
+
+// Main function, it's better to write void as an argument
+// It makes program more readable
+int main(void){
+
+  // Print statement, outputs to the console
+  cout<<"Let's go with g++!!";
+  // return 0;   // Tells the os, that the program execution was succesfull
+}
+
+// g++ {programFileName}.cpp -o {outputFileName}.(out | exe)
+// Run the file
+//  ./{outputFile}        - Powershell / bash
+//  call {outputFile}     - On CMD

Learn-CPP/Day-02/alias.cpp

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+#include<iostream>
+
+using namespace std;
+
+
+// Typedef is just like defining a new keyword with properties or behaviour of existing keyword
+typedef int rollno;     // rollno has properties of `int` now
+
+
+// enum is like defining a counter to the given set of items
+// By default this counter will start from 0, but we can specify the counter value for specific item, and others will have there counters updated
+enum working {mon=1, tue, wed, fri=5, sat, sun};
+//              1     2    3    5      6    7    
+
+int main(void){
+
+  rollno myRollNo = 46;     // myRollNo is of type `int` only, but this version of code is much more readable
+  cout<<"Size of 'myRollNo': "<<sizeof(myRollNo)<<endl<<endl;
+
+  // Value wed, will be 3, as it second after the mon(1)
+  cout<<"Value for wed: "<<working::wed<<endl;
+  cout<<"Value for sat: "<<working::sat<<endl;
+  // sat will be 6, as it comes just after fri(5)
+
+  return 0;
+}

Learn-CPP/Day-02/arithmetic.cpp

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+#include<iostream>
+using namespace std;
+
+int main(void){
+
+  char a = 'a';
+  char b = 'b';
+
+  char c = a + b;
+
+  cout<<"Printing directly the sum: "<<a+b <<endl;    // Output is 195(97 + 98), as internally char are stored as integers(ASCII values)
+  cout<<"Printing variable declared as `char`: "<<c<<endl;      // Outputs ├ because `c` is declared as the `char`, so 195 is converted back to character
+
+  // Integers
+
+  int Int1 = 5;
+  int Int2 = 7;
+
+  int sum = Int1 + Int2;
+  int diff = Int1 - Int2;
+  int product = Int1 * Int2;
+  int remainder = Int1 % Int2;    // It's called a modulo operator
+
+  cout<<"Working with Integers";
+  cout<<"Sum: "<<sum<<endl;
+  cout<<"Diff: "<<diff<<endl;
+  cout<<"Product: "<<product<<endl;
+  cout<<"Remainder: "<<remainder<<endl;
+
+  return 0;
+}

Learn-CPP/Day-02/data_modifiers.cpp

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+#include<iostream>
+
+using namespace std;
+
+int main(void){
+  /*
+
+  Primitive Data types: (int, char): Integral, bool, (float, double): Decimal
+  Data type    
+  signed        - Default one , one bit is reserved for the sign  
+  unsigned      - All bits are used, minimum number will be 0
+  short         - Almost half the size
+  long          - Almost double the size (depends on compiler)
+
+  */
+
+  int var = 5;
+  signed int svar = 6;
+  unsigned int uvar = 6;
+  short int shvar = 6;
+  long int lvar = 6;
+
+
+  cout<<"Size of int: "<<sizeof(var)<<endl;    // 4
+  cout<<"Size of signed int: "<<sizeof(svar)<<endl;   // 4
+  cout<<"Size of unsigned int: "<<sizeof(uvar)<<endl;   // 4
+  cout<<"Size of short int: "<<sizeof(shvar)<<endl;  // 2
+  cout<<"Size of long int: "<<sizeof(lvar)<<endl;   // 8
+
+  return 0;
+}

Learn-CPP/Day-02/uses.cpp

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+// Uses of typedef
+#include <iostream>
+
+using namespace std;
+
+// Instead of writing long long int, now we have to write only ll, to define a long long int
+typedef long long int ll;
+
+int main(void){
+  ll myLongInt;
+  cout<<sizeof(ll);
+}

Learn-CPP/Day-02/variables.cpp

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+#include<iostream>
+
+// Define namespace
+using namespace std;
+
+// Main function
+int main(void){
+  int a = 5;    // Declare a variable with integer data type
+  cout<<"Value of a: "<< a;    //output above integer
+  return 0;
+}

Learn-CPP/Day-03/advanced_conditionals.cpp

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+#include<iostream>
+
+using namespace std;
+
+int main(void){
+  // Comma(,) Operator returns last output
+  int a=5, b=6, c=7;
+  if(a<b, b>c){
+    cout<<"This is inside if statement";
+  }else{
+    cout<<"Though the first expression is true, else is getting processed...";
+  }
+  return 0;
+}

Learn-CPP/Day-03/menu.cpp

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+#include<iostream>
+using namespace std;
+
+int main(void){
+  string time, name;
+  cout<<"Enter your name: ";
+  cin>>name;
+
+  cout<<"What's the section of the day now?(morning, afternoon, eve): ";
+  cin>>time;
+
+  switch(time){     // May throw, switch quantity is not integer, in CPP version<17
+    case "morning":
+      cout<<"Good morning "<<name<<". Did you have breakfast yet?\n";
+      break;
+    case "afternoon":
+      cout<<"Good afternoon "<<name<<". Did you have lunch yet?\n";
+      break;
+    case "eve":
+    case "evening":
+      cout<<"Good evening "<<name<<". Did you have evening yet?\n";
+      break;
+    case "night":
+      cout<<"Good night "<<name<<".🥱\n";
+      break;
+
+    default:
+      cout<<"Well, maybe you're living in different dimension\a";
+  }
+
+  return 0;
+}

Learn-CPP/Day-03/relation.cpp

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+// Let's start with Relational and Logical operators
+#include<iostream>
+
+using namespace std;
+
+int main(void){
+
+  /*
+  Relational Operators
+  >     : Greater than
+  <     : Less than
+  >=    : Greater than or equal to
+  <=    : Greater than or equal to
+  ==    : Is equal
+  !=    : Not equal
+  */
+
+  int a = 8, b = 7;
+
+  cout<<"a = 8\nb = 7\n";
+  cout<<"a > b: "<<(a>b);
+  cout<<"\na < b: "<<(a<b);
+  cout<<"\na >= b: "<<(a>=b);
+  cout<<"\na <= b: "<<(a<=b);
+  cout<<"\na == b: "<<(a==b);
+  cout<<"\na != b: "<<(a!=b);
+
+
+  /*
+  Logical Operators
+  &&    : AND
+  ||    : OR
+  !     : NOT   : Unary Operator
+  */
+
+  int c = 5;
+  cout<<"\n\na>b and a>c  (Is a greatest of them): "<<(a>b) && (a>c);
+  cout<<"\nb>c and b>a  (Is b greatest of them): "<<(b>c) && (b>a);
+  cout<<"\nc>a and c>b  (Is a greatest of them): "<<(c>a) && (c>b);
+
+  return 0;
+}

Learn-CPP/Day-03/switch_case.cpp

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+#include<iostream>
+using namespace std;
+
+int main(void){
+  int choice;
+  cout<<"Enter your choice: ";
+  cin>>choice;
+
+  // Compare the value of `choice` variable
+  switch(choice){
+    case 0:
+      cout<<"Choice 0"<<endl;
+      break;
+    case 1:
+      cout<<"Choice 1"<<endl;
+      break;
+    case 2:
+      cout<<"Choice 2"<<endl;
+      break;
+
+    default:
+      cout<<"Not defined case"<<endl;
+  }
+  return 0;
+}

Learn-CPP/Day-03/ternary_max.cpp

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+// Find max of 3 numbers using ternary operators
+#include<iostream>
+using namespace std;
+
+int main(void){
+
+  int a, b, c, _MAX;
+  cout<<"Type in 3 integers: ";
+  cin>>a>>b>>c;
+
+  // Just use ternary operators to minimise the LOC (lines of code)
+  _MAX = (a>b && a>c)?a:(b>c?b:c);
+  cout<<"Maximum is: "<<_MAX;
+
+  return 0;
+}

Learn-CPP/Day-04/factorial.cpp

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+#include<iostream>
+using namespace std;
+
+int main(void){
+  int n;
+  unsigned long long int fact=1;
+  cout<<"Enter n: ";
+  cin>>n;
+
+  for(int i=2; i<=n; i++) fact*=i;
+  cout<<fact;
+
+  return 0;
+}

Learn-CPP/Day-04/hw/detectPrime.cpp

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+// Check if the number is prime
+#include<iostream>
+using namespace std;
+
+int main(void){
+  int num;
+  bool isPrime = true;
+
+  cout<<"Enter the number to check: ";
+  cin>>num;
+
+
+  // Check till i*i<=num
+  for(int i=2; i<num/2+1; i++){
+    if(num%i==0){
+      isPrime = false;
+      break;
+    }
+  }
+
+  cout<<num<<" is a "<<(isPrime?"Prime":"Composite")<<" number...";
+
+  return 0;
+}

Learn-CPP/Day-04/hw/sumNatural.cpp

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+// Find the sum of n natural numbers
+#include<iostream>
+using namespace std;
+
+int main(void){
+  int n, _sum = 0;
+
+  cout<<"Enter the number: ";
+  cin>>n;
+
+  for(int i=1; i<=n; i++) _sum += i;
+
+  // Alternative: cout<<n*(n+1)/2;
+
+  cout<<"Sum of "<<n<<" natural numbers = "<<_sum;
+
+  return 0;
+}

Learn-CPP/Day-04/intro_for.cpp

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+// Introduction to for loop
+#include<iostream>
+using namespace std;
+
+int main(void){
+
+  for(int i=1; i<10; i*=2) cout<<i<<" ";
+
+  return 0;
+}

Learn-CPP/Day-04/max_function.cpp

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+// Use of max function to get max of 3 variables
+#include<iostream>
+using namespace std;
+
+int main(void){
+  int a, b, c, _max;
+
+  cout<<"Type in 3 integers: ";
+  cin>>a>>b>>c;
+
+  // Only takes to arguments
+  _max = max(a, max(b, c));
+  cout<<"Greatest of these numbers: "<<_max;
+
+  return 0;
+}

Learn-CPP/Day-04/perfectNumEff.cpp

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+// Trying to find efficient algorithm to find if the number is a Perfect Number
+#include<iostream>
+#include<assert.h>
+using namespace std;
+
+typedef long int l;
+
+bool isPerfect(int num){
+  l sum = 1;
+  for (int i = 2; i < num/2; i++){
+    if(num%i == 0){
+      sum += i;
+      if(num/i >= num/2 && num/i != i){
+        sum += num/i;
+      }
+    }
+  }
+  return num==sum;
+}
+
+int main(void){
+  assert(isPerfect(6));
+  assert(isPerfect(28));
+  assert(isPerfect(496));
+  assert(!isPerfect(5));
+  cout<<"Yupp";
+}