#include<stdio.h>
#include"1bply.c"
main()
{
    double z;
    static double a[4][5]={   
                            {1.0, 2.0, 3.0, 4.0, 5.0},
                            {6.0, 7.0, 8.0, 9.0, 10.0},
                            {11.0, 12.0, 13.0, 14.0, 15.0},
                            {16.0, 17.0, 18.0,19.0, 20.0}};
    printf("\n");
    z=bply(a,4,5,0.6,-1.3);
    printf("p(0.60,-1.30)=%13.7e\n",z);
    printf("\n");
}

double bply(a,m,n,x,y)
int m,n;
double a[],x,y;
{
    int i,j;
    double u,s,xx;
    u=0.0;
    xx=1.0;
    for(i=0;i<=m-1;i++)
    {
       s=a[i*n+n-1]*xx;
        for(j=n-2;j>=0;j--)
            s=s*y+a[i*n+j]*xx;
        u=u+s;xx=xx*x;
    }
    return(u);
}

main函数调用bply(double a[],int m,int n,double x,double y)，为bply（a,4,5,0.6-1,3),可是实参a[4][5]是二维数组，可以赋给形参a[]吗，还有麻烦解释一下划线处什么意思？

就是对应的二维数组
因为内存是连续的