DouKaku?

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

const char TargetString[] = "METHINKSITISAWEASEL";
const int TargetStringLength = 20;

const char AlphabetTable[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const int AlphabetNum = strlen(AlphabetTable);


int getScore(char *s)
{
    //完全マッチで0が帰る。
    int score = 0;    
    for(int i = 0; i < TargetStringLength; ++i) {
        int d = TargetString[i] - s[i];
//        score -= d > 0 ? d : -d;    //差
        score -= !!d;                //ハミング距離
    }
    return score;    
}


void kousa(char *s1,char *s2)
{
    int r = rand() % TargetStringLength;
    //rの位置で交差させる
    for(int i = r; i < TargetStringLength; ++i){
        char t;
        t = s1[i];
        s1[i] = s2[i];
        s2[i] = t;
    }
}

void henni(char *s)
{
    //1文字を別の文字に変化させる
    s[rand() % (TargetStringLength - 1)] = AlphabetTable[rand() % AlphabetNum];
}

struct Gene{
    char gene[TargetStringLength];
    int result;
};

void GeneToResult(Gene *g)
{
    g->result = getScore(g->gene);
}


int compare(const void *_a,const void *_b)
{
    const Gene *a = (Gene*)_a;
    const Gene *b = (Gene*)_b;
    
    if (a->result > b->result){
        return -1;
    } else if (a->result < b->result) {
        return 1;
    }

    return 0;
}


int main()
{
    srand((unsigned int)time(NULL));

    //初期化
    const int GeneMax = 300;
    Gene genePool[GeneMax];

    for(int i = 0; i < GeneMax; ++i){
        //ランダムな文字列で埋め尽くす
        for(int j = 0; j < TargetStringLength - 1; ++j){
            genePool[i].gene[j] = AlphabetTable[rand() % AlphabetNum];
        }
        genePool[i].gene[TargetStringLength -1] = '\0';
        GeneToResult(&genePool[i]);    //スコアの取得
    }


    //進化させる
    for(int t = 0; t < 1000; t++) {
        //sort
        qsort(genePool,GeneMax,sizeof(Gene),&compare);

        //上位をprint
        printf("times = %d --------------------\n", t);
        for(int i = 0; i < 10; ++i){
            printf("Gene = %s, score = %d \n", genePool[i].gene, genePool[i].result);
        }
        getchar();

        //交叉、突然変異
        for(int i = GeneMax/2; i < GeneMax; i+=2){    //スコアの下位半分を捨てる
            char g1[TargetStringLength];
            char g2[TargetStringLength];
            strcpy(g1 , genePool[rand()%(GeneMax/2)].gene);    //適当な上位を選択
            strcpy(g2 , genePool[rand()%(GeneMax/2)].gene);
            kousa(g1, g2);    //交差
            henni(g1);        //変異
            henni(g2);
            strcpy(genePool[i].gene , g1);
            strcpy(genePool[i+1].gene , g2);
        }
        //評価
        for(int i = 0; i < GeneMax; ++i){
            GeneToResult(&genePool[i]);
        }
    }
}