大文本数据排序

大文本数据排序及二分法

#define  _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>

char **g_pp;//保存指针数组
#define N 28
struct index
{
    int *pindex;
    int length;
}allindex;//索引



int getN()
{
    FILE *pf = fopen("file.txt", "r");
    if (pf==NULL)
    {
        return -1;
    } 
    else
    {
        int i = 0;
        while (!feof(pf))
        {
            char str[50] = { 0 };
            fgets(str, 50, pf);//读取
            i++;
        }
        fclose(pf);
        return i;

    }
}
void eatN(char *str)
{
    while (*str!='\0')
    {
        if (*str=='\r' || *str=='\n')
        {
            *str = '\0';
        }

        str++;
    }

}

void initmem()
{
    g_pp = calloc(N, sizeof(char*));//分配指针数组
    FILE *pf = fopen("file.txt", "r");
    if (pf == NULL)
    {
        return -1;
    }
    else
    {
        for (int i = 0; i < N; i++)
        {
            char str[50] = { 0 };
            fgets(str, 50, pf);//读取
            g_pp[i] = calloc(strlen(str) + 1, sizeof(char));//分配
            
            sprintf(g_pp[i], str);//打印进去
            eatN(g_pp[i]);
            printf("%s", g_pp[i]);//显示测试


        }

        
        fclose(pf);
    

    }






}
int com(void *p1, void*p2)
{
    char **pp1 = p1;
    char **pp2 = p2;

    return strcmp(*pp1, *pp2);

}
void sort()
{
    qsort(g_pp, N, sizeof(char*), com);


}
void show()
{
    printf("\n此时状态\n");
    for (int i = 0; i < N;i++)
    {
        printf("\n%s", g_pp[i]);
    }
}
void writetofile()
{
    FILE *pf = fopen("filesort.txt", "w");
    for (int i = 0; i < N;i++)
    {
        char temp[100] = { 0 };
        sprintf(temp, "%s\n", g_pp[i]);
        fputs(temp, pf);
    }

    fclose(pf);
}


void init(char *path)
{
    printf("\n索引数组开始分配");
    allindex.length = N;
    allindex.pindex = calloc(N, sizeof(int));//分配内存
    printf("\n索引数组完成分配");

    printf("\n开始读取");
    FILE *pf = fopen("filesort.txt", "rb");//\r\n->\n
    if (pf == NULL)
    {
        return -1;
    }
    else
    {
        int alllength = 0;
        for (int i = 0; i < N; i++)
        {
            char str[50] = { 0 };
            fgets(str, 50, pf);
            allindex.pindex[i] = alllength;//错位从0开始

            int length = strlen(str);
            alllength += length;

        }



        fclose(pf);
    }
    printf("\n结束读取");

    printf("\n开始写入");
    FILE *pfw = fopen("index.txt", "wb");//写入索引
    fwrite(allindex.pindex, sizeof(int), allindex.length, pfw);
    fclose(pfw);//关闭
    printf("\n结束写入");


    free(allindex.pindex);


    





}
void qucik()
{
    printf("\n索引数组开始分配");
    allindex.length = N;
    allindex.pindex = calloc(N, sizeof(int));//分配内存
    printf("\n索引数组完成分配");

    printf("\n开始读取");
    FILE *pfw = fopen("index.txt", "rb");//写入索引
    fread(allindex.pindex, sizeof(int), allindex.length, pfw);
    fclose(pfw);//关闭
    printf("\n结束读取");
}



void main内存索引()
{
    //int num = 0;
    //scanf("%d", &num);
    //printf("%d", getN());
    /*initmem();
    sort();
    show();
    writetofile();*/
    //init("filesort.txt");
    qucik();
    FILE *pf = fopen("filesort.txt", "rb");
    while (1)
    {
        printf("\n请输入要读取的行数");
        int num = 0;
        scanf("%d", &num);

        fseek(pf, allindex.pindex[num], SEEK_SET);
        char str[128] = { 0 };
        fgets(str, 128, pf);//读取
        printf("\n%s", str);


    }
    fclose(pf);



    system("pause");
}

void main索引文件查找()
{


    FILE *pf1 = fopen("index.txt", "rb");
    FILE *pf2 = fopen("filesort.txt", "rb");
    while (1)
    {
        printf("\n请输入要读取的行数");
        int num = 0;
        scanf("%d", &num);

        int indexnum = 0;
        fseek(pf1, num*sizeof(int), SEEK_SET);
        fread(&indexnum, sizeof(int), 1, pf1);//读索引到indexnum

        fseek(pf2, indexnum, SEEK_SET);
        char str[128] = { 0 };
        fgets(str, 128, pf2);//读取
        printf("\n%s", str);

    }
    fclose(pf1);
    fclose(pf2);








    system("pause");
}
void eatg(char *str)
{
    while (*str!='\0')
    {

        if (*str=='-')
        {
            *str = '\0';
        }
        str++;
    }

}


void binsearch(char *searchstr)
{
    int tou = 0;
    int wei = N - 1;
    int flag = 0;
    while (tou <=wei)
    {
        int zhong = (tou + wei) / 2;
        char zhongstr[256] = { 0 };
        {
            FILE *pf1 = fopen("index.txt", "rb");
            FILE *pf2 = fopen("filesort.txt", "rb");


            int indexnum = 0;
            fseek(pf1, zhong*sizeof(int), SEEK_SET);
            fread(&indexnum, sizeof(int), 1, pf1);//读索引zhong到indexnum

            fseek(pf2, indexnum, SEEK_SET);
            fgets(zhongstr, 128, pf2);//读取
    
            fclose(pf1);
            fclose(pf2);
        }
        eatN(zhongstr);
        char pnewzhongstr[256] = { 0 };
        sprintf(pnewzhongstr, zhongstr);
        eatg(pnewzhongstr);//遇到-终止
        int res = strcmp(pnewzhongstr, searchstr);//1 0  -1
        if (res==0)
        {
            flag = 1;
            printf("%s", zhongstr);
            break;
        } 
        else if (res==1)
        {
            wei = zhong - 1;
        } 
        else
        {
            tou = zhong + 1;
        }

        
    }


    if (flag)
    {
        printf("\nfind");
    } 
    else
    {
        printf("\n not find");
    }


}


void main()
{


    char str[256] = { 0 };
    scanf("%s", str);
    binsearch(str);



    system("pause");
}