8-23.cpp

能判断二次函数是否有根

/*3208006411*/
#include<stdio.h>
void main()
{long int C(int n,int m);
int n,m;
int tap;
printf("Please input n,m\n");
scanf("%d,%d",&n,&m);
if((n>m)||n<0)
  printf("The input num is error.\n");
else
 tap=C(n,m);
printf("the tap is %d",tap);
}
long int C(int n,int m)
{long int t;
 if(n==0)
       t=1;
 else if(n==1)
       t=m;
 else if(n>m/2)
       t=C(m-n,m);
 else
       t=C(n,m-1)+C(n-1,m-1);
 return(t);

}