• Topics
  
  

• GCD & LCM

• Sieve

• Prime Factorization

• Finding Divisors

• Number of Divisors

• Sum of Divisors

• Euler phi (Euler's Totient Function)

• Factorial

• Extended Euclid

• Euler Theorem and Fermat's Little Theorem

• Big Integer in C++ for Contest

• Number Theory Level 1
  
  

• GCD & LCM

  • Concepts :

    • GCD
      
      
    • LCM
      
      

  • Related Problems :

    • UVA 10407 : Solution

    • UVA 10892 : Solution

    • UVA 11388 : Solution

    • UVA 11417 : Solution

    • UVA 11827 : Solution

    • UVA 12068 : Solution

    • UVA 408 : Solution

    • UVA 412 : Solution

• Sieve

  • Concepts :

    • General Sieve
      
      
    • Bitwise Sieve
      
      
    • Segmentation Sieve
      
      

  • RELATED PROBLEMS :

  • General Sieve :

    • UVA 10042 : Solution

    • UVA 10168 : Solution

    • UVA 10235 : Solution

    • UVA 10533 : Solution

    • UVA 10539 : Solution

    • UVA 10789 : Solution

    • UVA 406 : Solution

    • UVA 543 : Solution

    • UVA 686 : Solution

    • UVA 917 (Failed to add link) : Solution

  • Bitwise Sieve :

    • UVA 10394 : Solution

    • UVA 10699 : Solution

  • Segmentation Sieve :

    • SPOJ PRIME GENERATOR : Solution

    • UVA 10140 : Solution

• Prime factorization

  • Concepts

    • Prime Factorisation of a Number
      
      
    • Prime Factorization For multiple Queries By least prime method
      
      

  • Related Problems

    • Codeforces 1370C : Solution

    • UVA 10392 : Solution

    • UVA 10738 : Solution

    • UVA 11466 : Solution

    • UVA 583 : Solution

• Finding Divisors

  • Concepts

    • Finding Divisors of a Number N
      
      

  • Related Problems :

    • Light OJ 1014 : Solution
      
      
      

• Number Theory Level 2
  
  
  

  • Number of Divisors

    • Concepts

      • Number of Divisors for Any Number N
        
        
      • Pre Calculating Number of Divisors from 1 to N
        
        

    • Related Problems

      • Light OJ 1109 : Solution

      • Light OJ 1336 : Solution

      • SPOJ COMDIV : Solution

      • UVA 294 : Solution

  • Sum of Divisors

    • Concepts

      • Sum of Divisors For a N
        
        
      • Pre Calculating Sum of Divisors from 1 to N
        
        
      • Given a Number N find the sum of actual divisors from 1 to N in O(Sqrt(N))
        
        

    • Related Problems :

      • LightOJ 1054 : Solution

      • LightOJ 1098 : Solution

      • SPOJ DIVSUM : Solution

      • SPOJ DIVSUM2 : Solution

  • Euler Phi

    • Concepts :

      • Euler Phi for a Number N
        
        
      • Euler Phi From 1 to n in O(nloglogn)
        
        
      • How many Numbers from 1 to N has GCD(i,N) = g
        
        
      • Calculate the SUM = LCM(1,N) + LCM(2,N) + LCM(3,N)+... + LCM(N,N)
        
        

    • Related Problems :

      • Codeforces 1295D : Solution

      • LightOJ 1007 : Solution

      • SPOJ ETF : Solution

      • SPOJ LCMSUM : Solution

      • UVA 10179 : Solution

      • UVA 10820 : Solution

      • UVA 10990 : Solution

      • UVA 11064 : Solution

      • UVA 11327 : Solution

      • UVA 12425 : Solution

      • UVA 13132 : Solution

  • Factorial

    • Concepts
      
      

      • Digits of a factorial
        
        
      • Digits of a factorial in Different Base
        
        
      • Pre Calculating Digits of N! in different bases
        
        
      • Factorial Factorisation
        
        
      • Pre Calculating No of Factors from 1! to N!
        
        
      • Dividing a large factorial number N! by a number M
        
        
      • Number of Trailing Zeroes in N!
        
        
      • For a Given Number N how many Number system will have trailing zeroes
        
        
        

    • Related Problems
      
      

      • LightOJ 1028 : Solution

      • LightOJ 1035 : Solution

      • LightOJ 1045 : Solution

      • LightOJ 1090 : Solution

      • LightOJ 1340 : Solution

      • UVA 10061 : Solution

      • UVA 10780 : Solution

      • UVA 11415 : Solution

      • UVA 160 : Solution

      • UVA 884 : Solution
        
        
        

• Number Theory Level 3
  
  
  

  • Extended Euclid

    • Concepts
      
      

      • Explanation of Extended Euclid
        
        

    • Related Problems
      
      

      • UVA 10104 : Solution
        
        

  • Euler theorem and Fermat's Little theorem

    • Concepts
      
      

      • Explanation of Euler theorem and Fermat's Little theorem
        
        

  • Big Integer

    :

    • Concepts
      
      

      • Big Integer Library for Contests