Răspuns:
***************************** Triere **************************
#include <iostream>
using namespace std;
struct punct
{
int x,y,z;
}P;
int n,i,k,R;
int Distanta(punct P)
{
return P.x*P.x+P.y*P.y+P.z*P.z;
}
bool SolutiePosibila(punct P)
{
if (Distanta(P)<=R*R) return true;
else return false;
}
void PrelucrareaSolutiei(int &k)
{
++k;
}
int main()
{
cout << "Introdu raza sferei, R= "; cin >> R;
cout << "nr. de puncte, n= "; cin >> n;
cout << "Introduceti coordonatele x,y,z a " << n << " puncte \n";
for (i=1; i<=n; ++i)
{
cout << "pentru punctul " << i << " : ";
cin >> P.x >> P.y >> P.z;
if (SolutiePosibila(P))
PrelucrareaSolutiei(k);
}
cout << "In sfera se contin " << k << " puncte";
return 0;
}
Explicație:
************************ Greedy ***********************
#include <iostream>
using namespace std;
int n, A[100], B[100], m,x,i;
bool prim(int num)
{
if (num<2) return false;
if (num==2) return true;
if (num>2)
{
if (num%2==0) return false;
for (int d=3; d*d<=num; d+=2)
if (num%d==0) { return false; }
return true;
}
}
bool nuSeRepeta(int num)
{
int i;
bool nurepeta=true;
for (i=0; i<m; ++i)
if (num==B[i]) { nurepeta=false; break; }
return nurepeta;
}
bool ExistaElemente()
{
int i;
bool exista=false;
for (i=0; i<n; ++i)
if (prim(A[i]) && nuSeRepeta(A[i])) exista=true;
return exista;
}
void AlegeUnElement(int &x)
{
int i=0;
while (!(prim(A[i]) && nuSeRepeta(A[i]))) ++i;
x=A[i]; A[i]=0;
}
void IncludeElementul(int x, int &m)
{
B[m++]=x;
}
int main()
{
cout << "n= "; cin >> n;
cout << "introdu " << n << " numere naturale \n";
for (i=0; i<n; ++i)
cin >> A[i];
while (ExistaElemente())
{
AlegeUnElement(x);
IncludeElementul(x,m);
}
int suma=0;
for (i=0; i<m; ++i)
suma+=B[i];
cout << "Suma primelor= " << suma;
return 0;
}