By 袁壮苗 2017级计算机科学与技术专业
#include<stdio.h>
int main()
{
int a, b, c;
scanf("%d:%d",&a,&b);
if (a<12&&a>0)
printf("%d:%.2d AM\n",a,b);
else if (a==0)
printf("12:%.2d AM\n",b);
else if (a==12)
printf("%d:%.2d PM\n",a,b);
else {c=a-12;
printf("%d:%.2d PM\n",c,b);}
return 0;
}