行编译器

#include<stdio.h>
#include<string.h>
int main()
{
    char s[10];
    int a[200], n, m, t, top, x, i;
    scanf("%d", &t);
    while(t--)
    {
        top = -1;
        scanf("%d %d", &m, &n);
        memset(a,0,sizeof(a));
        for(i = 0; i <= n; i++)
        {
            getchar();
            scanf("%c", &s[0]);
            if(s[0] == 'P')
            {
                if(top + 1 < m)
                {
                    scanf("%d", &x);
                    a[++top] = x;
                }
                else
                {
                    printf("F\n");
                }
            }
            else if(s[0] == 'A')
            {
                if(top > -1)
                {
                    printf("%d\n", a[top]);
                }
                else
                {
                    printf("E\n");
                }
            }
            else if(s[0] == 'O')
            {
                if(top > -1)
                {
                    printf("%d\n", a[top]);
                    top--;
                }
                else
                {
                    printf("E\n");
                }
            }
        }
        printf("\n");
    }
    return 0;
}