From 6fd23da97fa9700f59c61a966b4bf7d25fa46b34 Mon Sep 17 00:00:00 2001
From: Paul Oliver <contact@pauloliver.dev>
Date: Thu, 29 Feb 2024 03:15:03 +0100
Subject: initial commit

---
 Population.cpp | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)
 create mode 100644 Population.cpp

(limited to 'Population.cpp')

diff --git a/Population.cpp b/Population.cpp
new file mode 100644
index 0000000..8c502b0
--- /dev/null
+++ b/Population.cpp
@@ -0,0 +1,95 @@
+#include "Population.hpp"
+
+Population::Population(unsigned popSize, unsigned eliteCount, unsigned chromosomeSize)
+:   m_popSize(popSize), m_eliteCount(eliteCount), m_chromosomeSize(chromosomeSize)
+{
+    m_fitnesses.resize(m_popSize, 0.f);
+    m_chromosomes.resize(m_popSize);
+    for (auto &i : m_chromosomes)
+    {
+        i.resize(m_chromosomeSize, 0.f);
+        for (auto &j : i)
+        {
+            j = realRand(-1.f, 1.f);
+        }
+    }
+}
+
+void Population::roulleteWheel()
+{
+    std::vector<Chromosome> newGeneration;
+
+    std::vector<unsigned> eliteIndexes(m_eliteCount, 0);
+    for (auto &i : eliteIndexes)
+    {
+        for (unsigned j = 0; j < m_popSize; ++j)
+        {
+            bool picked = false;
+            for (auto &k : eliteIndexes)
+            {
+                if (k == j)
+                {
+                    picked = true;
+                    break;
+                }
+            }
+            if (picked)
+            {
+                continue;
+            }
+            if (m_fitnesses[j] > m_fitnesses[i])
+            {
+                i = j;
+            }
+        }
+    }
+
+    for (auto &i : eliteIndexes)
+    {
+        newGeneration.push_back(m_chromosomes[i]);
+    }
+
+    unsigned fitnessSum = 0;
+    for (auto &i : m_fitnesses)
+    {
+        fitnessSum += i;
+    }
+
+    for (unsigned i = m_eliteCount; i < m_popSize; i += 2)
+    {
+        unsigned parentIndex = 0;
+        unsigned motherIndex = 0;
+        int randomParent = intRand(0, fitnessSum);
+        int randomMother = intRand(0, fitnessSum);
+
+        while (randomParent > 0)
+        {
+            randomParent -= m_fitnesses[parentIndex];
+            ++parentIndex;
+        }   --parentIndex;
+
+        while (randomMother > 0)
+        {
+            randomMother -= m_fitnesses[motherIndex];
+            ++motherIndex;
+        }   --motherIndex;
+
+        Chromosome child1;
+        Chromosome child2;
+
+        crossover(m_chromosomes[parentIndex], m_chromosomes[motherIndex], child1, child2);
+        mutate(child1);
+        mutate(child2);
+
+        newGeneration.push_back(child1);
+        newGeneration.push_back(child2);
+    }
+
+    if (newGeneration.size() < m_chromosomes.size())
+    {
+        newGeneration.push_back(newGeneration.back());
+    }
+
+    m_chromosomes = newGeneration;
+    m_fitnesses = std::vector<unsigned>(m_popSize, 0);
+}
-- 
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