diff --git a/src/GeneticAlgorithm/MainProcess.cpp b/src/GeneticAlgorithm/MainProcess.cpp
index 991374ffe6c84bfc421bf3d6ddb8bbd01c820e79..25f9897e5cf17ddc59192c16b59c4b38e373ad47 100644
--- a/src/GeneticAlgorithm/MainProcess.cpp
+++ b/src/GeneticAlgorithm/MainProcess.cpp
@@ -70,20 +70,24 @@ namespace GeneticAlgorithm {
         if (nullptr == this->population || nullptr == this->selectedChromosome || nullptr == this->newChromosome) {
             return;
         }
-        if (1 == this->keep && keep > 1) { // 之前是keep=1的话，会因为优化而不会排序
-            this->keep = keep;
-            this->sort(); // 先排序避免后满淘汰掉较优解
-        } else {
-            this->keep = keep;
+        if (this->keep != keep) { // 之前是keep=1的话，会因为优化而不会排序
+            if (1 == this->keep && keep > 1) { // 之前是keep=1的话，会因为优化而不会排序
+                this->keep = keep;
+                this->kill = this->numberOfChromosome - keep;
+                this->sort(); // 先排序避免后满淘汰掉较优解
+            } else {
+                this->keep = keep;
+                this->kill = this->numberOfChromosome - keep;
+            }
+            // 尺寸发生变化，删除旧的再申请新空间
+            delete[] this->selectedChromosome;
+            delete[] this->newChromosome;
+            this->selectedChromosome = new Chromosome*[2 * this->kill];
+            this->newChromosome = new Chromosome*[this->kill];
         }
-        this->kill = this->numberOfChromosome - keep;
-        // 尺寸发生变化，删除旧的再申请新空间
-        delete[] this->selectedChromosome;
-        delete[] this->newChromosome;
-        this->selectedChromosome = new Chromosome*[2 * this->kill];
-        this->newChromosome = new Chromosome*[this->kill];
         this->r = r;
         unsigned long i = 0;
+        this->maxFitness = this->population->getMaxFitnessChromosome()->getFitness();
         while (i < maxLoop && this->maxFitness < stopFitness) {
             this->select();
             this->crossover();
@@ -120,9 +124,9 @@ namespace GeneticAlgorithm {
     }
 
     void MainProcess::replaceChromosome(Chromosome* chromosome) {
-        Chromosome* max = this->population->getMaxFitnessChromosome();
+        Chromosome* maxChromosome = this->population->getMaxFitnessChromosome();
         for (unsigned long offset = this->numberOfChromosome - 1; offset + 2 > 1; offset--) {
-            if ((void*)this->population->getChromosome(offset) != (void*)max) {
+            if ((void*)this->population->getChromosome(offset) != (void*)maxChromosome) {
                 this->population->replaceChromosome(offset, chromosome);
                 return;
             }
diff --git a/src/GeneticAlgorithm/Population.cpp b/src/GeneticAlgorithm/Population.cpp
index 82af57504db56ead910130f65163712f41d99281..f4673f87197f62ee72d19a460ca2e6868f68e44b 100644
--- a/src/GeneticAlgorithm/Population.cpp
+++ b/src/GeneticAlgorithm/Population.cpp
@@ -22,50 +22,35 @@ namespace GeneticAlgorithm {
     }
 
     bool Population::setChromosome(unsigned long offset, Chromosome *chromosome) {
-        if (offset < this->numberOfChromosome && !this->chromosomeArray[offset]) {
-            if (this->isMaxFitnessChromosomeCache) {
-                if (this->maxFitnessChromosomeCache->getFitness() > chromosome->getFitness()) {
-                    if (this->maxFitnessChromosomeOffset != offset) {
-                        this->chromosomeArray[offset] = chromosome;
-                    } else {
-                        this->isMaxFitnessChromosomeCache = false;
-                        this->chromosomeArray[offset] = chromosome;
-                    }
-                } else {
-                    this->maxFitnessChromosomeCache = chromosome;
-                    this->maxFitnessChromosomeOffset = offset;
-                    this->chromosomeArray[offset] = chromosome;
-                }
+        if (offset >= this->numberOfChromosome) {
+            return false;
+        }
+        if (nullptr == this->chromosomeArray[offset]) {
+            this->chromosomeArray[offset] = chromosome;
+            this->isMaxFitnessChromosomeCache = false;
+            return true;
+        }
+        Chromosome* origin = this->chromosomeArray[offset];
+        if ((void*)origin == (void*)chromosome) {
+            return true;
+        }
+        if (this->isMaxFitnessChromosomeCache) {
+            if ((void*)(this->maxFitnessChromosomeCache) == (void*)chromosome) {
+                return false;
+            }
+            if (this->maxFitnessChromosomeCache->getFitness() > chromosome->getFitness()) {
+                this->isMaxFitnessChromosomeCache = false;
             } else {
-                this->chromosomeArray[offset] = chromosome;
+                this->maxFitnessChromosomeCache = chromosome;
             }
-            return true;
         }
-        return false;
+        this->chromosomeArray[offset] = chromosome;
+        delete origin;
+        return true;
     }
 
     bool Population::replaceChromosome(unsigned long offset, Chromosome *chromosome) {
-        if (offset < this->numberOfChromosome && this->chromosomeArray[offset]) {
-            delete this->chromosomeArray[offset];
-            if (this->isMaxFitnessChromosomeCache) { // 这段逻辑与setChromosome里面的相同
-                if (this->maxFitnessChromosomeCache->getFitness() > chromosome->getFitness()) {
-                    if (this->maxFitnessChromosomeOffset != offset) {
-                        this->chromosomeArray[offset] = chromosome;
-                    } else {
-                        this->isMaxFitnessChromosomeCache = false;
-                        this->chromosomeArray[offset] = chromosome;
-                    }
-                } else {
-                    this->maxFitnessChromosomeCache = chromosome;
-                    this->maxFitnessChromosomeOffset = offset;
-                    this->chromosomeArray[offset] = chromosome;
-                }
-            } else {
-                this->chromosomeArray[offset] = chromosome;
-            }
-            return true;
-        }
-        return false;
+        return this->setChromosome(offset, chromosome);
     }
 
     Chromosome* Population::getChromosome(unsigned long offset) {