65 lines
1.3 KiB
C++
65 lines
1.3 KiB
C++
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#include<conio.h>
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#include<iostream>
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#include<sstream>
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#include<new>
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//In Zusammenarbeit mit Nils Werner
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//Zwei verschiedene nat<61>rliche Zahlen,
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//von denen wechselseitig jeweils eine Zahl gleich der Summe der echten Teiler der anderen Zahl ist,
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//bilden ein Paar befreundeter Zahlen.
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int divSum(int number);
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void program();
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int main()
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{
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program();
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std::cout << "\n\nProgrammende!";
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getch();
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return(0);
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}
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int divSum(int number)
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{
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int sum = 0;
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for (int idx = 1; idx*2 <= number; idx++) if(number%idx==0) sum += idx;
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return (sum);
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}
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void program()
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{
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unsigned long long limit = 0;
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std::string input;
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do{
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std::cout<< "Gib ein Limit ein: ";
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getline(std::cin, input);
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std::stringstream(input)>>limit;
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if(limit>=ULLONG_MAX || limit<0) std::cerr << "Error: Dieses Limit ist nicht m\x94glich. ";
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}while(limit>=ULLONG_MAX || limit<0);
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try
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{
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unsigned long long *number = new unsigned long long[limit+1];
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std::cout<< "befreundete Zahlen sind:\n";
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for (int idx = 220; idx<= limit; idx++)
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{
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number[idx] = divSum(idx);
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if(idx > number[idx]) if (idx==number[number[idx]]) std::cout << idx << " und " << number[idx] << "\n";
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}
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delete[] number;
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}
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catch(std::bad_alloc& ba)
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{
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std::cerr << "Error: Es konnte kein Array dieser Gr\x94\xE1 \be erstellt werden. ";
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program();
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}
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}
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