供参考:
#include<stdio.h>
int main()
{
int i,j,n;
char ch='F',c;
//scanf("%c",&ch);
n = ch - 'A';
for(i=0;i<=n;i++)
{
c = ch;
for(j=0;j<=i;j++)
printf("%c",c--);
printf("\n");
}
return 0;
}