Find out if a rectangle is inside another rectangle [C]

Question

So I have two rectangles, the user has to input the bottom left point (x1,y1, but y1 is always 0) and the top right point (x2,y2), and I have to find out if one of them is

Answer 1

Below is comparing the sides of the inner rectangle to the sides of the outer rectangle

if Right2 < Right1 && Left2 > Left1 && Top2 > Top1 && Bottom2 < Bottom1

Implementation:

struct RECT
{
    double x,y, w,h;

    RECT(double a,double b,double c,double d)
    {
    x=a; y=b; w=c; h=d;
    }
};


bool contains(RECT R1, RECT R2)
{
    if (   (R2.x+R2.w) < (R1.x+R1.w)
        && (R2.x) > (R1.x)
        && (R2.y) > (R1.y)
        && (R2.y+R2.h) < (R1.y+R1.h)
        )
    {
        return true;
    }
    else
    {
        return false;
    }
}

Answer 2

Well, by definition one rectangle is inside of another if all the points of the inner rectangle are within the outer rectangle. Using a bit of geometry you can boil it down to checking whether the two opposite corners of the inner rectangle are in the outer rectangle.