int main() {
stack<string> doubtStack;
doubtStack.push("How to reverse a string?");
doubtStack.push("Why binary search needs sorted array?");
doubtStack.push("Difference between vector and array?");
doubtStack.push("How to calculate time complexity?");
cout << "Total doubts: " << doubtStack.size() <<
endl;
while(!doubtStack.empty()) {
cout << "Resolving doubt: " << doubtStack.top()
<< endl;
doubtStack.pop();
}
vector<int> scores = {75,88,92,60,85,78};
sort(scores.begin(), scores.end());
cout << "Sorted scores: ";
for(auto s : scores) cout << s << " ";
cout << endl;
vector<int> rev(scores.rbegin(), scores.rend());
cout << "Highest to lowest: ";
for(auto s : rev) cout << s << " ";
cout << endl;
int sum = 0;
for(auto s : scores) sum += s;
cout << "Total marks: " << sum << endl;
cout << "Average marks: " << (double)sum /
scores.size() << endl;
cout << "All doubts resolved. Keep learning!" <<
endl;
return 0;
}
