用位图排序无重复数据集实例代码（C++版）

#define MAX_NUM 16777216//最大的数,也就是需要的位
#define BYTE_NUM (1+MAX_NUM/8)//字节数
#define MASK 0x07

void setAllZero(unsigned char *p,long size);
void setOne(unsigned char *p,long loc);
int find(unsigned char *p,long loc);
bool getSorted(unsigned char *bitmap,char *fileName);
bool setBitmap(unsigned char *bitmap,char *fileName);
int bitmapSort();
int main(){
    return bitmapSort();
}
int bitmapSort(){
    unsigned char *bitmap;    //位图指针
    bitmap = (unsigned char *)malloc(BYTE_NUM*sizeof(unsigned char));
    if(bitmap == NULL){
        printf("Malloc failed\n");
        return -1;
    }   
    setAllZero(bitmap,BYTE_NUM);//将位图所有位设置为0
    setBitmap(bitmap,"phoneNumber.txt");//扫描待排文件，将位图对应位设置为1
    getSorted(bitmap,"bitmapSort.txt");    //扫描位图，将位图为1的位号输出到文件
    free(bitmap);//释放位图
    return 0;
}
/***********设置待排序数据的位图**************/
bool setBitmap(unsigned char *bitmap,char *fileName){
    FILE *readFp;
    printf("Setting bitmap...\n");
    readFp = fopen(fileName,"r");
    if(readFp == NULL)
        return false;   
    long phoneNum=0;
    while(fscanf(readFp,"%ld\n",&phoneNum) != EOF){
        setOne(bitmap,phoneNum);//将    phoneNum位设置为1   
    }
    fclose(readFp);
    return true;
}
/*****顺序遍历位图输出记录，从而实现排序****************/
bool getSorted(unsigned char *bitmap,char *fileName){
    printf("Search bitmap...\n");
    FILE *writeFp;
    writeFp = fopen(fileName,"w");
    if(writeFp == NULL)
        return false;
    long phoneNum=0;
    for(phoneNum = 0; phoneNum < MAX_NUM; phoneNum += 1){
        if(find(bitmap,phoneNum)){
            fprintf(writeFp,"%ld\n",phoneNum);
        }
    }
    fclose(writeFp);
    return true;
}
/******先将位图清零********/
void setAllZero(unsigned char *bitmap,long size){
    for(long i=0;i<size;i++)
        *(bitmap+i) &= 0;
}
/*************************************************
将指定的位置为1
(loc>>3)相当于整除2^3=8，即定位到字节数，MASK=0x07,loc&MASK相当于loc%8
***************************************************/
void setOne(unsigned char *bitmap,long loc){
    *(bitmap+(loc>>3)) |= (1<<(loc&MASK));//
}

/******查找指定的位是否为1********/
int find(unsigned char *bitmap,long loc){
    return ((*(bitmap+(loc>>3))) & (1<<(loc&MASK))) == (1<<(loc&MASK));   
}
 

int main(){
    FILE *readFp,*writeFp;
    readFp = fopen("phoneNumber1.txt","r");       
    writeFp = fopen("bitsetSorted.txt","w");   
    bitset<MAX_NUM> bitmap;
    for(long i=0;i<MAX_NUM;i++){//先将位图初试化为0
        bitmap.set(i,0);
    }
    printf("Begin set bitmap...\n");
    long number = 0;
    while(fscanf(readFp,"%ld\n",&number) != EOF){
        bitmap.set(number,1);//将number所在位设置为1       
    }
    printf("Begin search bitmap...\n");
    for(long i=0;i<MAX_NUM;i++){
        if(bitmap[i] == 1)//将位1的位输出到已排序文件
            fprintf(writeFp,"%ld\n",number);
    }
    fclose(writeFp);
    fclose(readFp);
}