/* Tank problem solver using ES(Evolution Strategy) */

import java.lang.*;
import java.io.*;
import java.util.*;

public class ES {

    boolean[][] chromosome;
    //遺伝子配列[固体番号][遺伝子内の座標]
    int MAXLOOP = 1000;
    Random random;
    long seed;
    double fitness[]; //遺伝子の適応度を記録
    int MAXRANGE=1000; //敵戦車の範囲 0-1000m

    //for test
    public static void main(String[] args){

        int population=100;
        int chromLen=16; //遺伝子の長さ
        long seed=0;
        ES es = new ES(population, chromLen, seed);
        es.start();
    }

    public ES(int population, int chromLen, long seed){
        chromosome = new boolean[population][chromLen];
        this.seed = seed;
        fitness = new double[population];
    }

    public void start(){
        this.init();

	int loop=1;
        while(true){
	    System.out.print("loop:"+loop);
            this.eval();
	    printChromosome(0);
	    
	    if(loop>=MAXLOOP) {
		break;
	    }
            select();
            geneticOperation();
	    loop++;
        }

	printChromosome(0); //output best Chromosome
    }

    void init(){
	random = new Random(seed);
        for(int i=0; i<chromosome.length; i++){//population
            for(int j=0; j<chromosome[0].length; j++){
                chromosome[i][j]=random.nextBoolean();
            }
        }
    }

    void eval(){
        for(int i=0; i<chromosome.length; i++){
            fitness[i]=fitness(chromosome[i]);
        }

        //bubble sort
        //smallest fitness at index 0

        for(int i=0; i<chromosome.length-1; i++){
            for(int j=chromosome.length-1; j>i; j--){
                if(fitness[j]<fitness[i]){
                    swap(i,j);
                }
            }
	}
    }

    //return value of 0 is perfect fitness
    double fitness(boolean[] chrom){
	//max_range = 1000; max_angle = Math.PI/2; max_speed = 100;
	//assume d = A*speed + B*angle
	//assume fixed angle(=0.8)
	//therefore d = A*speed + B
	//speed = (d-B)/A

        double totalError =0;
        for(int i=0; i<10; i++){
	    double target=(MAXRANGE/10.0)*(i+1.0);//10等分に範囲を切り分け

	    double a=valueA(chrom);
	    double b=valueB(chrom);
	    //System.out.println("A:"+a+" B:"+b);

	    double speed = (target - b)/a;
	    //System.out.println("speed:"+speed);

	    //find actual distance using speed
	    double distance = (speed * speed * Math.sin( (0.8) * 2.0 ))/9.8 ;
	    //System.out.println("distance:"+distance);

	    totalError += Math.abs(target-distance);
	    //System.out.println("error:"+totalError);
        }

        return totalError;
    }

    double valueA(boolean[] chrom){
	double value = 0.0;
	value += (chrom[1]==true?1:0)*64;
	value += (chrom[2]==true?1:0)*32;
	value += (chrom[3]==true?1:0)*16;
	value += (chrom[4]==true?1:0)*8;
	value += (chrom[5]==true?1:0)*4;
	value += (chrom[6]==true?1:0)*2;
	value += (chrom[7]==true?1:0)*1;
	if(chrom[0]==true){
	    value=value*-1;
	}

	return value;
    }

    double valueB(boolean[] chrom){
	double value = 0.0;
	value += (chrom[9]==true?1:0)*64;
	value += (chrom[10]==true?1:0)*32;
	value += (chrom[11]==true?1:0)*16;
	value += (chrom[12]==true?1:0)*8;
	value += (chrom[13]==true?1:0)*4;
	value += (chrom[14]==true?1:0)*2;
	value += (chrom[15]==true?1:0)*1;

	if(chrom[8]==true){
	    value=value*-1;
	}

	return value;
    }


    void swap(int i, int j){
        //swap fitness
        double tmp = fitness[i];
        fitness[i]=fitness[j];
        fitness[j]=tmp;

        //swap chromosome
        boolean[] tmpchrom=new boolean[chromosome[0].length];
        for(int k=0; k<chromosome[0].length; k++){
            tmpchrom[k]=chromosome[i][k];
            chromosome[i][k]=chromosome[j][k];
            chromosome[j][k]=tmpchrom[k];
        }
    }

    void select(){
        //elite selection only. select best half
        for(int i=0; i<chromosome.length/2; i++){
            copy(i,i+chromosome.length/2);
        }
    }

    void copy(int from, int to){
        //copy chromosome
        for(int i=0; i<chromosome[0].length; i++){ 
            chromosome[to][i]=chromosome[from][i];
        }
    }

    void geneticOperation(){
        //do not crossover
        //only mutation
        mutation();
	//crossover();
    }

    void mutation(){
        //do not mutation best chromosome (Elitist strategy)
        for(int i=1; i<chromosome.length; i++){
	    mutate(i);
	}
    }

    void mutate(int i){
	int j=random.nextInt(chromosome[0].length); //randomly choose location
	if(chromosome[i][j]==true){
	    chromosome[i][j]=false;
	}else{ //currently false
	    chromosome[i][j]=true;
	}
    }

    void printChromosome(int i){
	System.out.print("fitness"+fitness[0]+" ");
        for(int j=0; j<chromosome[0].length; j++){
            if(chromosome[i][j]==true){
                System.out.print(1);
            }else{
                System.out.print(0);
	    }
	}
	System.out.println();
    }
}