#include "mex.h"
#include "math.h"
typedef unsigned int size_t;

void mexFunction(int nlhs, mxArray* plhs[],int nrhs, const mxArray* prhs[])
{
    size_t Alen=0;
    size_t Blen=0;
    size_t i=0;
    double *dataA=NULL;
    double *dataB=NULL;
    double sum=0;
    mxArray *pSum=NULL;
    if(nrhs<2)
    {
        mexPrintf("parameters are fewer than 2\n");
        plhs=NULL;
        nlhs=0;
        return;
    }
    Alen=length(prhs[0]);
    Blen=length(prhs[1]);
    if(Alen!=Blen)
    {
        mexPrintf("dim of para inconsists.\n");
        return;
    }
//     mexPrintf("A %d B %d\n",Alen,Blen);
    dataA=mxGetPr(prhs[0]);
    dataB=mxGetPr(prhs[1]);
//     mexPrintf("%f\n",dataA[0]);
    for(i=0;i<Alen;i++)
    {
        sum+=pow(dataA[i]-dataB[i],2);
    }
    sum=sqrt(sum);
    pSum=mxCreateScalarDouble(sum);
    if(nlhs>0)
    {
        plhs[0]=pSum;
    }
    else
    {
        mexPrintf("must have at least one out para.\n");
        return;
    }
    
}

size_t length(const mxArray* p)
{
    size_t m=0;
    size_t n=0;
    m=mxGetM(p);
    n=mxGetN(p);
    if(m>n)
    {
        return m;
    }
    return n;
}