implement reproductive skew

src/common.odin

@@ -5,7 +5,6 @@ import "core:container/bit_array"
 Chromosome :: ^bit_array.Bit_Array
 Population :: [POPULATION_SIZE]Chromosome
 
-POPULATION_SIZE :: 1000
 GENERATIONS :: 100
 POPULATION_SIZE :: 1000
 ELITISM_COUNT :: 10
@@ -15,7 +14,6 @@ CROSSOVER_RATE :: 0.7
 MUTATION_RATE :: 0.015
 RANDOM_SEED :: u64(42)
 OUTPUT_FILE :: "output/data.csv"
-ELITISM_COUNT :: 50
 
 Problem :: struct {
 	name:            string,

src/ga.odin

@@ -211,21 +211,27 @@ create_offspring :: proc(pop: ^Population, fitnesses: []f64, maximize: bool) ->
 		offspring[i] = clone_chromosome(pop[elite_idx[i]])
 	}
 
-	for i := ELITISM_COUNT; i < POPULATION_SIZE; i += 2 {
+	offspring_count := POPULATION_SIZE - ELITISM_COUNT - SKEW
+	for i := ELITISM_COUNT; i < ELITISM_COUNT + offspring_count; i += 2 {
 		parent1 := roulette_selection(pop, fitnesses, maximize)
 		parent2 := roulette_selection(pop, fitnesses, maximize)
 
 		child1, child2 := uniform_crossover(parent1, parent2)
 
 		bit_flip_mutation(child1)
-		if i + 1 < POPULATION_SIZE {
+		offspring[i] = child1
+
+		if i + 1 < ELITISM_COUNT + offspring_count {
 			bit_flip_mutation(child2)
 			offspring[i + 1] = child2
 		} else {
 			bit_array.destroy(child2)
 		}
+	}
 
-		offspring[i] = child1
+	for i := ELITISM_COUNT + offspring_count; i < POPULATION_SIZE; i += 1 {
+		parent := roulette_selection(pop, fitnesses, maximize)
+		offspring[i] = clone_chromosome(parent)
 	}
 
 	return offspring