使用遗传算法解决ackley函数的最小值

#include<iostream> #include<vector> #include<algorithm> #include<ctime> #include<cmath> #include<fstream> using namespace std; struct fun_value{ int key; double value; }; bool cmp(fun_value a,fun_value b){ return a.value>b.value; } ofstream outfile("result.txt",ios::in); class GA{ public: int pc,pm; int n,m; double max,mean; vector<vector<int> >s; vector<fun_value>f; GA(int n,int m,int pc,int pm){ this->n=n; this->m=m; this->pc=pc; this->pm=pm; srand(unsigned(time(0))); int i,j; vector<int>s1(m); for(i=0;i<n;i++){ for(j=0;j<m;j++) s1.push_back(rand()%2); s.push_back(s1); s1.clear(); } } void select(); void cross(); double n2to10(int two[]); double fun(vector<int>all_two); }; void GA::select(){ int size=s.size(); int i; double value=0; vector<vector<int> >s2; vector<fun_value>::iterator it; f.resize(size); for(i=0;i<size;i++){ f[i].key=i; f[i].value=fun(s[i]); } sort(f.begin(),f.end(),cmp); max=f[0].value; for(it=f.begin();it!=f.end();it++) value+=(*it).value; mean=mean/size; outfile<<f[0].value<<endl; for(i=0;i<n;i++) s2.push_back(s[f[i].key]); s.clear(); s.assign(s2.begin(),s2.end()); } void GA::cross(){ srand(unsigned(time(0))); vector<int>sc; vector<vector<int> >scross; double maxoftwo; int i,j,num1,num2,pos; if(f[num1].value>f[num2].value) maxoftwo=f[num1].value; else maxoftwo=f[num2].value; for(i=0;i<n/2;i++){ num1=rand()%n; num2=rand()%n; pos=rand()%m; if(maxoftwo>=mean) pc=0.9-0.3*(maxoftwo-mean)/(max-mean); else pc=0.9; if(((float)rand()/RAND_MAX)<pc){ sc.insert(sc.end(),s[num1].begin(),s[num1].begin()+pos); sc.insert(sc.end(),s[num2].begin()+pos,s[num2].end()); scross.push_back(sc); } else{ scross.push_back(s[num1]); } sc.clear(); if(((float)rand()/RAND_MAX)<pc){ sc.insert(sc.end(),s[num2].begin(),s[num2].begin()+pos); sc.insert(sc.end(),s[num1].begin()+pos,s[num1].end()); scross.push_back(sc); } else { scross.push_back(s[num2]); } sc.clear(); if(f[num1].value>=mean) pm=0.1-0.099*(max-f[num1].value)/(max-mean); else pm=0.1; if(((float)rand()/RAND_MAX)<pm){ pos=rand()%m; scross[i][pos]=abs(scross[i][pos]-1); } if(f[num2].value>=mean) pm=0.1-0.099*(max-f[num2].value)/(max-mean); else pm=0.1; if(((float)rand()/RAND_MAX)<pm){ pos=rand()%m; scross[i+1][pos]=abs(scross[i+1][pos]-1); } } s.insert(s.end(),scross.begin(),scross.end()); } double GA::n2to10(int two[]){ double ten_value=0; int i; for(i=0;i<20;i++) ten_value=ten_value*2+two[19-i]; ten_value=-32.0+ten_value*64.0/(pow(2,20)-1); return ten_value; } double GA::fun(vector<int>all_two){ double part1,part2,ten_value,eval; int i,j,k; int two[20]; for(i=0;i<50;i++){ part1=part2=0.0; k=i*20; for(j=0;j<20;j++) two[j]=all_two[k++]; ten_value=n2to10(two); part1+=ten_value*ten_value; part2+=cos(2*3.14*ten_value); } eval=20*exp(-0.2*sqrt(part1/50))+exp(part2/50); return eval; } int main(){ GA ga(1500,1000,0.75,0.02); int gnmax=2500; int i; for(i=0;i<gnmax;i++){ ga.select(); ga.cross(); } cout<<ga.f[0].value; }