.编写一个计算组合数的函数combinNum(int m,int n).计算结果由函数返回. 计算组

#include unsigned long combinNum(int m,int n) { int i; unsigned long x=1; if(nm)return 0; for(i=m;i>m-n;i--) x=x*i/(m+1-i); return x; } void main() { int m,n; scanf("%d%d",&m,&n); printf("%ld\n",combinNum(m,n));