Solving N-Queen problem using Genetic Algorithm

The aim of N-Queens Problem is to place N queens on an N x N chessboard, in a way so that no queen is in conflict with the others.

• Gene: An individual is characterized by a set of variables
• Chromosome: Genes are joined into a string to form a Chromosome (solution). A chromosome is a set of parameters which define a proposed solution to the problem that the genetic algorithm is trying to solve
• Population: The set of all solutions
• Fitness Function: Pairs of non-attacking queens (say for N=6, Fmax= 6C2 = 6*5/2 = 15)
• Crossover: Also called recombination, is a genetic operator used to combine the genetic information of two parents to generate new offspring
• Mutation: It alters one or more gene values in a chromosome from its initial state

• Step 1: A random chromosome is generated
• Step 2: Fitness value of the chromosome is calculated
• Step 3: If fitness is not equal to Fmax
• Step 4: Reproduce (crossover) new chromosome from 2 randomly selected best chromosomes
• Step 5: Mutation may take place
• Step 6: New chromosome added to population
• Repeat Step 2 to 6 until a chromosome (solution) with Fitness value = Fmax is found

Since most of the process is random, it doesn't always take the same time to converge to a solution. If you want to dig deep, watch this.