一百行以下有哪些給力代碼？

語言不限，給力種類不限。
請給出簡介、出處。
謝謝大家！

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#include & // smallpt, a Path Tracer by Kevin Beason, 2008
#include & // Make : g++ -O3 -fopenmp smallpt.cpp -o smallpt
#include & // Remove "-fopenmp" for g++ version &< 4.2 struct Vec { // Usage: time ./smallpt 5000 xv image.ppm double x, y, z; // position, also color (r,g,b) Vec(double x_=0, double y_=0, double z_=0){ x=x_; y=y_; z=z_; } Vec operator+(const Vec b) const { return Vec(x+b.x,y+b.y,z+b.z); } Vec operator-(const Vec b) const { return Vec(x-b.x,y-b.y,z-b.z); } Vec operator*(double b) const { return Vec(x*b,y*b,z*b); } Vec mult(const Vec b) const { return Vec(x*b.x,y*b.y,z*b.z); } Vec norm(){ return *this = *this * (1/sqrt(x*x+y*y+z*z)); } double dot(const Vec b) const { return x*b.x+y*b.y+z*b.z; } // cross: Vec operator%(Vecb){return Vec(y*b.z-z*b.y,z*b.x-x*b.z,x*b.y-y*b.x);} }; struct Ray { Vec o, d; Ray(Vec o_, Vec d_) : o(o_), d(d_) {} }; enum Refl_t { DIFF, SPEC, REFR }; // material types, used in radiance() struct Sphere { double rad; // radius Vec p, e, c; // position, emission, color Refl_t refl; // reflection type (DIFFuse, SPECular, REFRactive) Sphere(double rad_, Vec p_, Vec e_, Vec c_, Refl_t refl_): rad(rad_), p(p_), e(e_), c(c_), refl(refl_) {} double intersect(const Ray r) const { // returns distance, 0 if nohit Vec op = p-r.o; // Solve t^2*d.d + 2*t*(o-p).d + (o-p).(o-p)-R^2 = 0 double t, eps=1e-4, b=op.dot(r.d), det=b*b-op.dot(op)+rad*rad; if (det&<0) return 0; else det=sqrt(det); return (t=b-det)&>eps ? t : ((t=b+det)&>eps ? t : 0);
}
};
Sphere spheres[] = {//Scene: radius, position, emission, color, material
Sphere(1e5, Vec( 1e5+1,40.8,81.6), Vec(),Vec(.75,.25,.25),DIFF),//Left
Sphere(1e5, Vec(-1e5+99,40.8,81.6),Vec(),Vec(.25,.25,.75),DIFF),//Rght
Sphere(1e5, Vec(50,40.8, 1e5), Vec(),Vec(.75,.75,.75),DIFF),//Back
Sphere(1e5, Vec(50,40.8,-1e5+170), Vec(),Vec(), DIFF),//Frnt
Sphere(1e5, Vec(50, 1e5, 81.6), Vec(),Vec(.75,.75,.75),DIFF),//Botm
Sphere(1e5, Vec(50,-1e5+81.6,81.6),Vec(),Vec(.75,.75,.75),DIFF),//Top
Sphere(16.5,Vec(27,16.5,47), Vec(),Vec(1,1,1)*.999, SPEC),//Mirr
Sphere(16.5,Vec(73,16.5,78), Vec(),Vec(1,1,1)*.999, REFR),//Glas
Sphere(600, Vec(50,681.6-.27,81.6),Vec(12,12,12), Vec(), DIFF) //Lite
};
inline double clamp(double x){ return x&<0 ? 0 : x&>1 ? 1 : x; }
inline int toInt(double x){ return int(pow(clamp(x),1/2.2)*255+.5); }
inline bool intersect(const Ray r, double t, int id){
double n=sizeof(spheres)/sizeof(Sphere), d, inf=t=1e20;
for(int i=int(n);i--;) if((d=spheres[i].intersect(r))d&f.y f.x&>f.z ? f.x : f.y&>f.z ? f.y : f.z; // max refl
if (++depth&>5) if (erand48(Xi)&.1?Vec(0,1):Vec(1))%w).norm(), v=w%u;
Vec d = (u*cos(r1)*r2s + v*sin(r1)*r2s + w*sqrt(1-r2)).norm();
return obj.e + f.mult(radiance(Ray(x,d),depth,Xi));
} else if (obj.refl == SPEC) // Ideal SPECULAR reflection
return obj.e + f.mult(radiance(Ray(x,r.d-n*2*n.dot(r.d)),depth,Xi));
Ray reflRay(x, r.d-n*2*n.dot(r.d)); // Ideal dielectric REFRACTION
bool into = n.dot(nl)&>0; // Ray from outside going in?
double nc=1, nt=1.5, nnt=into?nc/nt:nt/nc, ddn=r.d.dot(nl), cos2t;
if ((cos2t=1-nnt*nnt*(1-ddn*ddn))&<0) // Total internal reflection return obj.e + f.mult(radiance(reflRay,depth,Xi)); Vec tdir = (r.d*nnt - n*((into?1:-1)*(ddn*nnt+sqrt(cos2t)))).norm(); double a=nt-nc, b=nt+nc, R0=a*a/(b*b), c = 1-(into?-ddn:tdir.dot(n)); double Re=R0+(1-R0)*c*c*c*c*c,Tr=1-Re,P=.25+.5*Re,RP=Re/P,TP=Tr/(1-P); return obj.e + f.mult(depth&>2 ? (erand48(Xi)&