Помогите написать код на C++

vector < char > arr(n);
for (int i = 0; i < n; i++) arr[i] = (char)(rand() % 25 + 65);
for each (char i in arr) cout << i << ' ';
cout << endl;
{ vector < char > temp(n);
for (int i = 0, j = n - 1; i < n; i++, --j) temp[j] = arr[i];
arr = temp; }
for each (char i in arr) cout << i << ' ';

=================

vector < int > arr(n);
for (int i = 0; i < n; i++) {
arr[i] = rand() % 10;
cout << arr[i] << ' ';
}
cout << endl;
sort(arr.begin(), arr.end(), less < int > ());
for each (int i in arr) cout << i << ' ';

==============

int matrix[M][N];
vector < int > B(N);
for (int i = 0, j; i < M; i++) {
for (j = 0; j < N; j++) {
matrix[i][j] = rand() % 10;
cout << matrix[i][j] << ' ';
if (matrix[i][j] && B[j] != 1) B[j] = 1;
}
cout << endl;
}
cout << endl;
for each (int i in B) cout << i << ' ';

==============

string str = "1 4 0 0 3 5 2 9 3 2 1 8 5 7 2 6 1";
cout << str << endl;
for (int i = 0, temp; i < (int)str.size(); i += 2) {
if (!(temp = (int)str[i] - 48)) continue;
if (temp % 2 == 0)
cout << str[i] << ' ';
}

Возьми пособие по C++.

for(char*p=arr,*j=arr+n;p++<j--;*p^=*j^=*p^=*j);

действительно не сложный, думаю справишься.