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class Temp{public:    Temp() { ++ N; Sum += N; }    static void Reset() { N = 0; Sum = 0; }    static unsigned int GetSum() { return Sum; }private:    static unsigned int N;    static unsigned int Sum;};unsigned int Temp::N = 0;unsigned int Temp::Sum = 0;unsigned int Sum_Solution1(unsigned int n){    Temp::Reset();    Temp *a = new Temp[n];    delete []a;    a = NULL;    return Temp::GetSum();}

class A;A* Array[2];class A{public:    virtual unsigned int Sum (unsigned int n)     {         return 0;     }};class B: public A{public:    virtual unsigned int Sum (unsigned int n)     {         return Array[!!n]->Sum(n-1) + n;     }};int Sum_Solution2(int n){    A a;    B b;    Array[0] = &a;    Array[1] = &b;    int value = Array[1]->Sum(n);    return value;}

typedef unsigned int (*fun)(unsigned int);unsigned int Solution3_Teminator(unsigned int n) {    return 0;}unsigned int Sum_Solution3(unsigned int n){    static fun f[2] = {Solution3_Teminator, Sum_Solution3};     return n + f[!!n](n - 1);}

template 
   
     struct Sum_Solution4{    enum Value { N = Sum_Solution4
    
     ::N + n};};template <> struct Sum_Solution4<1>{    enum Value { N = 1};};template <> struct Sum_Solution4<0>{    enum Value { N = 0};};