9.2 KiB
- Task: construct an empty deque
- Task: construct deque with 5 copies of value
- Task: construct deque from initializer list
- Task: construct deque from a range
- Task: access element at index with bounds checking
- Task: access element at index with operator[]
- Task: access first and last elements
- Task: iterate over deque with begin/end
- Task: reverse iterate over deque
- Task: check if deque is empty
- Task: get size of deque
- Task: clear all elements from deque
- Task: push elements to back of deque
- Task: push elements to front of deque
- Task: pop elements from back of deque
- Task: pop elements from front of deque
- Task: emplace back into deque
- Task: emplace front into deque
- Task: resize deque
- Task: insert element at position
- Task: insert multiple copies
- Task: insert range into deque
- Task: erase single element
- Task: erase range of elements
- Task: swap two deques
- Task: emplace at specific position
- Task: assign new contents to deque
- Task: assign from range
- Task: use deque as FIFO queue
Task: construct an empty deque cpp deque production
Front
Write how to create an empty deque of ints
Back
std::deque<int> d;Task: construct deque with 5 copies of value cpp deque production
Front
Write how to create a deque with 5 elements, all initialized to 42
Back
std::deque<int> d(5, 42); // {42, 42, 42, 42, 42}
Task: construct deque from initializer list cpp deque production
Front
Write how to create a deque initialized with {1, 2, 3}
Back
std::deque<int> d = {1, 2, 3};Task: construct deque from a range cpp deque production
Front
Write how to create a deque from a vector's begin/end iterators
Back
std::vector<int> v = {1, 2, 3, 4, 5};
std::deque<int> d(v.begin(), v.end());Task: access element at index with bounds checking cpp deque production
Front
Write how to safely access element at index 2 in a deque (throws on invalid index)
Back
std::deque<int> d = {10, 20, 30};
int x = d.at(2); // returns 30, throws std::out_of_range if invalid
Task: access element at index with operator[] cpp deque production
Front
Write how to access element at index 1 using operator[]
Back
std::deque<int> d = {10, 20, 30};
int x = d[1]; // returns 20, no bounds check
Task: access first and last elements cpp deque production
Front
Write how to get the first and last element of a deque
Back
std::deque<int> d = {10, 20, 30};
int first = d.front(); // 10
int last = d.back(); // 30
Task: iterate over deque with begin/end cpp deque production
Front
Write a range-based for loop over a deque using iterators
Back
std::deque<int> d = {1, 2, 3};
for (auto it = d.begin(); it != d.end(); ++it) {
std::cout << *it << " ";
}
// or:
for (int x : d) { std::cout << x << " "; }Task: reverse iterate over deque cpp deque production
Front
Write how to iterate backwards through a deque using reverse iterators
Back
std::deque<int> d = {1, 2, 3};
for (auto it = d.rbegin(); it != d.rend(); ++it) {
std::cout << *it << " "; // prints 3 2 1
}Task: check if deque is empty cpp deque production
Front
Write how to check if a deque is empty
Back
std::deque<int> d;
if (d.empty()) { /* ... */ }Task: get size of deque cpp deque production
Front
Write how to get the number of elements in a deque
Back
std::deque<int> d = {1, 2, 3};
std::size_t n = d.size(); // returns 3
Task: clear all elements from deque cpp deque production
Front
Write how to remove all elements from a deque
Back
std::deque<int> d = {1, 2, 3};
d.clear(); // size becomes 0
Task: push elements to back of deque cpp deque production
Front
Write how to add elements 10, 20, 30 to the back of a deque
Back
std::deque<int> d;
d.push_back(10);
d.push_back(20);
d.push_back(30);Task: push elements to front of deque cpp deque production
Front
Write how to add elements 30, 20, 10 to the front of a deque (pushing in that order)
Back
std::deque<int> d;
d.push_front(30); // {30}
d.push_front(20); // {20, 30}
d.push_front(10); // {10, 20, 30}
Task: pop elements from back of deque cpp deque production
Front
Write how to remove the last element from a deque
Back
std::deque<int> d = {1, 2, 3};
d.pop_back(); // {1, 2}
Task: pop elements from front of deque cpp deque production
Front
Write how to remove the first element from a deque
Back
std::deque<int> d = {1, 2, 3};
d.pop_front(); // {2, 3}
Task: emplace back into deque cpp deque production
Front
Write how to construct a pair in-place at the back of a deque (without copying)
Back
std::deque<std::pair<int,int>> d;
d.emplace_back(1, 2); // constructs pair{1,2} directly
Task: emplace front into deque cpp deque production
Front
Write how to construct an element in-place at the front of a deque
Back
std::deque<std::string> d;
d.emplace_front("hello"); // constructs string directly at front
Task: resize deque cpp deque production
Front
Write how to resize a deque to 10 elements, filling new spots with 0
Back
std::deque<int> d = {1, 2, 3};
d.resize(10); // {1, 2, 3, 0, 0, 0, 0, 0, 0, 0}
d.resize(5, 42); // resize to 5, filling with 42 if growing
Task: insert element at position cpp deque production
Front
Write how to insert value 99 at the beginning of a deque
Back
std::deque<int> d = {1, 2, 3};
d.insert(d.begin(), 99); // {99, 1, 2, 3}
Task: insert multiple copies cpp deque production
Front
Write how to insert 5 copies of value 42 starting at position begin
Back
std::deque<int> d = {1, 2, 3};
d.insert(d.begin(), 5, 42); // {42, 42, 42, 42, 42, 1, 2, 3}
Task: insert range into deque cpp deque production
Front
Write how to insert all elements from a vector into a deque at position begin
Back
std::deque<int> d = {1, 2, 3};
std::vector<int> v = {10, 20};
d.insert(d.begin(), v.begin(), v.end()); // {10, 20, 1, 2, 3}
Task: erase single element cpp deque production
Front
Write how to erase the element at position begin + 1 in a deque
Back
std::deque<int> d = {1, 2, 3};
d.erase(d.begin() + 1); // {1, 3}
Task: erase range of elements cpp deque production
Front
Write how to erase elements from begin to begin+2 (2 elements) in a deque
Back
std::deque<int> d = {1, 2, 3, 4, 5};
d.erase(d.begin(), d.begin() + 2); // {3, 4, 5}
Task: swap two deques cpp deque production
Front
Write how to swap the contents of two deques
Back
std::deque<int> d1 = {1, 2, 3};
std::deque<int> d2 = {4, 5, 6};
d1.swap(d2); // d1 = {4,5,6}, d2 = {1,2,3}
Task: emplace at specific position cpp deque production
Front
Write how to construct a pair in-place at position begin of a deque
Back
std::deque<std::pair<int,int>> d;
d.emplace(d.begin(), 1, 2); // constructs pair{1,2} at begin
Task: assign new contents to deque cpp deque production
Front
Write how to replace all contents of a deque with 5 copies of 99
Back
std::deque<int> d = {1, 2, 3};
d.assign(5, 99); // {99, 99, 99, 99, 99}
Task: assign from range cpp deque production
Front
Write how to replace deque contents with all elements from a vector
Back
std::deque<int> d;
std::vector<int> v = {10, 20, 30};
d.assign(v.begin(), v.end()); // {10, 20, 30}
Task: use deque as FIFO queue cpp deque production
Front
Write how to use deque as a FIFO queue (enqueue 1, 2, 3 then dequeue all)
Back
std::deque<int> q;
q.push_back(1); // enqueue
q.push_back(2);
q.push_back(3);
while (!q.empty()) {
std::cout << q.front() << " ";
q.pop_front(); // dequeue
}
// Output: 1 2 3