检查输入是否已输入数组

我试图在我的代码中包含一个检查以查看是否已输入值 . 我的程序以（月日）的格式对日期列表进行排序，这个月作为字符输入 .

这是应该发生什么的一个例子 .

3 - 要排序的n个日期数 . 然后是格式的n个日期（月份日）1月1日01月1日00 00 2月99然后用户检查是否以（月份日）的格式输入日期1 1 00

最终输出：

日期按时间顺序排序然后告诉用户他们所做的检查是否在他们输入的数据中（这是我需要帮助的）

这就是我试图检查是否输入了值的方法 .

int k;
int input[j];
scanf("%d", &input[j]);

for (i = 0; k < n; k++) {
    if (ar[i] == input[j]) {

        printf("Yes value is there");
    }
    else {

        printf("No value isn't");
    }
}

下面我发布了我的工作程序，没有尝试检查 . 运行它只返回按时间顺序排序的日期 .

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

/* constants for max chars, max day, max year, max size */
enum { MAXC = 12,
    MAX_DAY = 31,
    MAX_YEAR = 12,
    MAX_SIZE = 1000 };
typedef struct {
    char month[MAXC]; /* either make static or allocate separately */
    unsigned day;
    unsigned year;
    int monthnum;
} date;

/* empty character remaining in stdin */
void empty_stdin()
{
    int c;
    while ((c = getchar()) != '\n' && c != EOF) {
    }
}

int fix_year(int year)
{
    if (year >= 90)
        return 1900 + year;
    return 2000 + year;
}

/* sort struct date on year */
int sort(const void* a, const void* b)
{
    date* date1 = (date*)a;
    date* date2 = (date*)b;

    /*if (date2->year != date1->year)
        return (date1->year > date2->year) - (date1->year < date2->year);*/

    int year1 = fix_year(date1->year);
    int year2 = fix_year(date2->year);
    //return year2 - year1;

    //int month1 = date1->month;
    //int month2 = date2->month;

    if (date2->year != date1->year) {
        return year2 - year1;
    }
    else if (date2->month != date1->month) {
        int month1 = date1->month;
        int month2 = date2->month;

        return month2 - month1;
    }
    else if (date2->day != date1->day) {
        //else sort day
        int day1 = date1->month;
        int day2 = date2->month;

        /*int daycompare = date2->day - date1->day;
    return -daycompare;
    */

        return day2 - day1;
    }

    return 0;
}

/* output n elements of array of struct date */
void output(date* ar, int n)
{
    int i;

    printf("\nOutput sorted by year:\n\n");

    for (i = 0; i < n; i++)
        printf("  %s %d %d\n", ar[i].month, ar[i].day, ar[i].year);
}

int main(void)
{

    int i, n;
    date* ar = NULL;

    while (1) { /* obtain valid 'n', compare with using fgets below */

        int rtn; /* varaible to save return of scanf -- always validate */

        //printf ("Enter number of dates to be entered (between 1 & 1000): ");
        if ((rtn = scanf("%d", &n)) != 1) { /* if conversion failed */
            if (rtn == EOF) { /* test for user cancelation of input */
                fprintf(stderr, "note: user canceled input, exiting.\n");
                return 0;
            } /* otherwise simply an invalid input */
            fprintf(stderr, "error: invalid input.\n");
            goto tryagain;
        }

        if (n < 0) { /* invalid input < 0 */
            fprintf(stderr, "error: invalid input (n < 0).\n");
            goto tryagain;
        }

        if (n > MAX_SIZE) { /* invalid input > MAX_SIZE */
            fprintf(stderr, "error: invalid input (n > %d).\n", MAX_SIZE);
            goto tryagain;
        }

        break; /* if we are here - we have a good value, break */

    tryagain:; /* label for goto to jump over break */

        empty_stdin(); /* empty characters that remain in input buffer */
    }

    empty_stdin(); /* empty characters that remain in input buffer */

    /* allocate array of struct ar, n elements */
    if ((ar = malloc(sizeof *ar * n)) == NULL) {
        fprintf(stderr, "error: virtual memory exhausted.\n");
        return 1;
    }

    /* provide format instructions */
    //printf ("Enter the date (month day year)\n"
    // "  format, e.g.:  Jan 18 2017\n\n");

    for (i = 0; i < n; i++) { /* loop until all elements filled */

        char buf[MAX_DAY + 1] = "", ans[MAXC] = "";

        //printf (" date[%2d] : ", i + 1);    /* prompt for input */

        /* if fgets return is NULL, EOF encountered */
        if (fgets(buf, MAX_DAY + 1, stdin) == NULL) {
            fprintf(stderr, "note: user canceled input, exiting.\n");
            return 0;
        }

        if (*buf == '\n') { /* if first char is '\n', user just hit enter */
            printf("no input provided, quit (y/n)? ");
            if (fgets(ans, MAXC, stdin) && (*ans == 'y' || *ans == 'Y'))
                return 0;
            else if (!*ans) { /* if ans NULL, EOF encountered */
                fprintf(stderr, "note: user canceled input, exiting.\n");
                return 0;
            }
        }

        /* parse with sscanf, validate 3 conversion took place */
        if (sscanf(buf, "%11s %u %u", ar[i].month, &ar[i].day, &ar[i].year) != 3) {
            fprintf(stderr, "error: invalid input.\n");
            continue;
        }

        /* only increment if valid sscanf conversion took place */
    }

    //scanf("%d", &date_list[i].day);
    qsort(ar, n, sizeof(date), sort); /* sort by year */

    output(ar, n); /* output results */

    free(ar); /* free ar - you allocate it, you free it */

    return 0;
}