[求助] ]# define NUM (M+1)*M/2
# include "stdio.h"
# define N 2
# define M (N+1)+N
# define NUM (M+1)*M/2
main()
{ int i,n=0;
printf("%d\n",N);
printf("%d\n",NUM);
for (i=1;i<=NUM;i++)
{n++;
printf("%d",n);}
printf("\n");
}
为什么NUM的值为19,请高手们帮忙解释一下~!~~~~