Find maximum difference between two numbers in an array (or) find max profit that can be made in given stock rates for few consecutuve days

int MaxDiff(int arr[], int siz)
{
    int i,j;
    int maxDiff = 0;
    int minNum  = arr[0];
    
    for(i=1;i<siz;i++)
    {
        if( (arr[i]-minNum) >  maxDiff )
            maxDiff = (arr[i]-minNum);

        if(arr[i] < minNum)
           minNum = arr[i];
    }

    return maxDiff;
}