C++字符串输入问题

我在写程序时，发现了一个问题：
C++字符串循环输入不了！

```c++
#include
#define For(i,a,b) for(int i = a;i < b;i++)
#define ll long long
#define ull unsigned long long
#define loop while(true)
using namespace std;
char str[10000];
char j[27] = "abcdefghijklmnopqrstuvwxyz",m[27] = "fghijklmnopqrstuvwxyzabcde";
int main()
{
    int ans;
    scanf("%d",&ans);
    if(ans == 1)
    {
        printf("Please enter your string:");
        fgets(str,10000,stdin);
        int len = strlen(str);
        for(int i = 0;i < len;i++)
        {
            str[i] = m[str[i]-'a'];
        }
        cout<<"is "<if(ans == 2)
    {
        printf("Please enter your string:");
        fgets(str,10000,stdin);
        int len = strlen(str);
        for(int i = 0;i < len;i++)
        {
            if(str[i] == ' ') continue;
            if(str[i]-'a'-5 < 0) str[i] = j[26+(str[i]-'a'-5)]; 
            else str[i] = j[str[i]-'a'-5]; 
        }
        cout<<"is "<return 0;
}

```

把

fgets(str,10000,stdin);

改成

cin.getline(str,10000);

试一试？

你代码里似乎并没有循环输入字符串的地方啊