// #1#include <iostream>using namespace std;int main() { unsigned int n; cout << "N = "; cin >> n; float a[n][n], sum = 0; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { cout << "a[" << i << "][" << j << "] = "; cin >> a[i][j]; sum += a[i][j]; } } float avg = sum / (n * n); cout << "Среднее арифметическое - " << avg << ", начинаю замену..."; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (a[i][j] < 0) { cout << "a[" << i << "][" << j << "] = " << a[i][j] << " < 0, заменяю на " << avg << "..."; a[i][j] = avg; } } } cout << "Изменённый массив:"; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { cout << a[i][j]; if ( !(j == n - 1) ) cout << ' '; } if ( !(i == n - 1) ) cout << ''; } return 0;}// #2#include <iostream>using namespace std;const unsigned short int n = 7;int main() { int a[n][n], max; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { cout << "a[" << i << "][" << j << "] = "; cin >> a[i][j]; } } max = a[0][0]; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if ( (a[i][j] > max) && (i + j > n + 1) ) max = a[i][j]; } } cout << "Максимум ниже побочной диагонали: " << max; return 0;}