70 lines
1.7 KiB
C++
70 lines
1.7 KiB
C++
#include <iostream>
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using namespace std;
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void Pos(int* a, int n) {
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int count = 0;
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for (int i = 0; i < 3 && i < n; ++i)
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if (a[i] > 0) ++count;
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cout << "The number of the first 3 elements > 0: " << count << endl;
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}
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void Show1(int* a, int n) {
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cout << "The last 3 elements: ";
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for (int i = (n >= 3 ? n - 3 : 0); i < n; ++i)
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cout << a[i] << " ";
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cout << endl;
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}
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void Show2(int* a, int n) {
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int* b = new int[n];
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for (int i = 0; i < n; ++i) b[i] = a[i];
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for (int i = 0; i < n-1; ++i)
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for (int j = i+1; j < n; ++j)
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if (b[i] > b[j]) { int t = b[i]; b[i] = b[j]; b[j] = t; }
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cout << "The three smallest elements: ";
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for (int i = 0; i < 3 && i < n; ++i) cout << b[i] << " ";
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cout << endl;
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delete[] b;
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}
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typedef void (*searchFunc)(int*, int);
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void service(int* a, int n, searchFunc f) {
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f(a, n);
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}
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int main() {
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srand(time(NULL));
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int n;
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cout << "n(n>=3)= ";
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cin >> n;
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if (n < 3) {
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cerr << "Error: size Array!!";
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return 1;
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}
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int* arr = new int[n];
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for (int i = 0; i < n; ++i)
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arr[i] = rand() % 41 - 20;
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cout << "Array: ";
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for (int i = 0; i < n; ++i) cout << arr[i] << " ";
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cout << endl;
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searchFunc arrFunc[3] = { Pos, Show1, Show2 };
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cout << "Menu:\n"
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<< "1) The number of the first 3 elements > 0\n"
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<< "2) Show the last 3 items\n"
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<< "3) Display the 3 smallest elements\n"
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<< "Select an action (1-3): ";
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int choice;
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cin >> choice;
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if (choice >= 1 && choice <= 3)
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service(arr, n, arrFunc[choice-1]);
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else
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cout << "Incorrect choice!\n";
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delete[] arr;
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return 0;
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} |