c - 从 csv 文件读入二维数组并使用 c 对数组进行排序

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在我的 csv 文件中，目前我有类似的数据

45454, 32, 78, C, 67
45452, 22, 38, C, 34

我想将数据添加到二维数组中并对其进行排序。目前我正在使用这种方法

#include<stdio.h>
#include<conio.h>
#include<String.h>

void getData(char *buff);
int main()
{
    FILE *fp = fopen("file1.csv", "r");
    int count = -1;
    do
    {
        char buff[1024];
        fgets(buff, 1024, (FILE*)fp);
        count++;
        if(count != 1)
        {
            printf(buff);
            getData(buff);
        }
    }
    while((getc(fp))!= EOF);


}
void getData(char buff[])
{
    char *token = strtok(buff,",");
    int counter=0;

    while( token != NULL )
    {
        counter++;
        printf(" %s\n",token);
        token = strtok(NULL,",");
    }
}

但我想使用 fgets 和 sscanf 读取数据并将它们存储到单维 VLA(可变长度数组)中我怎样才能做到这一点？

Answer 1

您实际上并不需要二维数组。你只需要一个数组来保存你的行。给你:

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

struct row {
    int id;
    int col1;
    int col2;
    char col3;
    int col4;
};

int cmp(const void *a1, const void *a2) {
    const struct row *r1 = a1;
    const struct row *r2 = a2;
    return r1->id - r2->id;
}

void line_to_row(char *buff, struct row *r)
{
    char *saveptr;
    char *token = strtok_r(buff, ",", &saveptr);
    if (token == NULL) {
        exit(1);
    }
    r->id = atoi(token);

    token = strtok_r(buff, ",", &saveptr);
    if (token == NULL) {
        exit(1);
    }
    r->col1 = atoi(token);

    token = strtok_r(buff, ",", &saveptr);
    if (token == NULL) {
        exit(1);
    }
    r->col2 = atoi(token);

    token = strtok_r(buff, ",", &saveptr);
    if (token == NULL) {
        exit(1);
    }

    while (*token != '\0') {
        r->col3 = *token;
        token++;
    }

    r->col4 = atoi(buff + 1);
}

int main()
{
    FILE *fp = fopen("file1.csv", "r");
    if (fp == NULL) {
        exit(1);
    }
    char buff[1024 + 1];
    int c, i = 0, len = 10;
    struct row *rows = malloc(sizeof(*rows) * len);
    struct row *temp = rows;

    while (fgets(buff, 1024, (FILE*)fp)) {
        if (i == len - 1) {
            len += 10;
            temp = realloc(rows, sizeof(*rows) * len);
            if (temp == NULL) {
                exit(1);
            }
            rows = temp;
        }
        line_to_row(buff, &rows[i]);
        i++;
    }
    fclose(fp);

    if (i == 0) {
        return 0;
    }

    len = i;
    temp = realloc(rows, sizeof(*rows) * len);

    if (temp == NULL) {
        exit(1);
    }

    rows = temp;

    qsort(rows, len, sizeof(*rows), &cmp);

    for (i = 0; i < len; i++) {
        printf("%d\n", rows[i].id);
    }
    free(rows);
    return 0;
}