请教：关于C语言bsearch的用法

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

typedef int (*compfn)(const void*, const void*);

struct date
{
    char m[10]; /**< January 等等 */
    int  d;     /**< 日 1 2 3 4 5 6.。。。。。 */
int  y;     /**< 年 90-99 00-12 */
};


int cmp_month(const char *m1, const char *m2)
{
    int i, n, n1, n2;
    static const char *months[] = {
        "January",
        "February",
        "March",
        "April",
        "May",
        "June",
        "July",
        "August",
        "September",
        "October",
        "November",
        "December",
    };

    n = sizeof(months) / sizeof(months[0]);
    n1 = n2 = -1;
    for (i = 0; i < n; ++i) {
        if (n1 < 0 && strcmp(m1, months[i]) == 0)
            n1 = i;
        if (n2 < 0 && strcmp(m2, months[i]) == 0)
            n2 = i;
        if (n1 >= 0 && n2 >= 0)
            break;
    }

    return n1 - n2;
}


int cmp_year(const void *v1, const void *v2)
{
    int temp;
    const struct date *y1, *y2;
 
    y1 = (const struct date *)v1;
    y2 = (const struct date *)v2;

 
    if ((temp = (y1->y != y2->y)) != 0) {
        if (y1->y >= 70 && y2->y >= 70)
            return y1->y - y2->y;
        if (y1->y >= 70 && y2->y <  70)
            return -1;
        if (y1->y <  70 && y2->y <  70)
            return y1->y - y2->y;
        if (y1->y <  70 && y2->y >= 70) 
 
            return +1;
    }
}


int cmp_day(const void *v1, const void *v2)
{
const struct date *d1, *d2;
d1 = (const struct date *)v1;
    d2 = (const struct date *)v2;

return d1->d - d2->d;
}

int main(int argc, char *argv[])
{
    int i, n,;
            struct date date[] = {
{"January", 1, 01},
{"January", 1, 00},
{"February", 28, 99},
{"July", 17, 12},
{"September", 10, 12},
{"July", 1,00},
{"June", 30, 90},
{"August", 25, 06},
{"May", 27, 07},
{"October", 1, 03},
    };
 
    n = sizeof(date) / sizeof(date[0]);

qsort(date, n, sizeof(struct date), &cmp_day);
        qsort(date, n, sizeof(struct date), (compfn)cmp_month);
qsort(date, n, sizeof(struct date), &cmp_year);

    for (i = 0; i < n; ++i)
        printf("%s %d %02d\n", date[i].m, date[i].d, date[i].y);


    return 0;
}

如何使用bsearch（）查找 January 01 01 是否在date里面？ c 语言 struct bsearch
[解决办法]
楼主没有理解前面的哪个帖子？
仔细查看了一下2楼的代码， 57行有错误！

    if ((ret = (d1->y != d2->y)) != 0) {

改为

    if ((ret = (d1->y - d2->y)) != 0) {

下面的代码加上了bsearch

/**
 * @file    datesort.c
 * @brief   
 */

struct date
{
    char m[20]; /**< January 等等 */
    int  d;     /**< 日 1 2 3 4 5 6.。。。。。 */
    int  y;     /**< 年 90-99 00-12 */
};

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

int cmp_month(const char *m1, const char *m2)
{
    int i, n, n1, n2;
    static const char *months[] = {
        "January",
        "February",
        "March",
        "April",
        "May",
        "June",
        "July",
        "August",
        "September", 
 
        "October",
        "November",
        "December",
    };

    n = sizeof(months) / sizeof(months[0]);
    n1 = n2 = -1;
    for (i = 0; i < n; ++i) {
        if (n1 < 0 && strcmp(m1, months[i]) == 0)
            n1 = i;
        if (n2 < 0 && strcmp(m2, months[i]) == 0)
            n2 = i;
        if (n1 >= 0 && n2 >= 0)
            break;
    }

    return n1 - n2;
}

int cmp_date(const void *v1, const void *v2)
{
    int ret;
    const struct date *d1, *d2;

    d1 = (const struct date *)v1;
    d2 = (const struct date *)v2;

    if ((ret = (d1->y - d2->y)) != 0) {
        if (d1->y >= 70 && d2->y >= 70)
            return ret;
        if (d1->y >= 70 && d2->y <  70)
            return -1;
        if (d1->y <  70 && d2->y <  70)
            return ret;
        if (d1->y <  70 && d2->y >= 70)
            return +1;
    }
    
    if ((ret = cmp_month(d1->m, d2->m)) != 0)
        return ret;

    return d1->d - d2->d;
}

int main(int argc, char *argv[])
{
    int i, n;

    struct date *ptr;
    struct date key = {"January", 01, 01};
    struct date date[] = {
        {"January", 1, 01},
        {"January", 1, 00},
        {"February", 28, 99},
        {"July", 17, 12},
        {"September", 10, 12},
        {"July", 1,00},
        {"June", 30, 90},
        {"August", 25, 06}, 
 
        {"May", 27, 07},
        {"October", 1, 03},
    };

    n = sizeof(date) / sizeof(date[0]);
    qsort(date, n, sizeof(struct date), &cmp_date);

    for (i = 0; i < n; ++i)
        printf("%s %d %d\n", date[i].m, date[i].d, date[i].y);

    ptr = bsearch(&key, date, n, sizeof(struct date), &cmp_date);
    if (ptr != NULL) {
        printf("\n");
        printf("date[%d]:\n", (int)(ptr - date));
        printf("%s %d %d\n", ptr->m, ptr->d, ptr->y);
    }
    return 0;
}