为什么，解决不了输入的问题（数据最后没回车）

#include <stdio.h>
int main()
{
    int n = 0, i = 0, num = 0,hr;
    char ch;
    char a[400];

    while ((ch = getchar()) != '\n')
    {
        n++;
        a[i++] = ch;
    }
    hr = n;

    for (int j = 2; j < n; j++)
    {
        for (int p = 0; p < n; p++)
        {
            ch = getchar();
            a[i++] = ch;
        }
        ch = getchar();
    }
    for (int p = 0; p < n; p++)
    {
        ch = getchar();
        a[i++] = ch;
    }

    n = i;
    ch = '0';
    printf("%d ", hr);
    for (int j = 0; j < n; j++)
    {
        if (a[j] == ch)
        {
            num++;
        }
        else
        {
            printf("%d ", num);
            num = 1;
            switch (ch)
            {
            case'1':
                ch = '0';
                break;
            case'0':
                ch = '1';
                break;
            }

        }
    }
    printf("%d", num);
    return 0;
}