leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
Log | Files | Refs | README | LICENSE |
commit0c4be2dd7e1849bf5f09add4e4952f5619fe1521
parentb63855cf7ac47e69cc0454549065d2c5cbb4f430
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateSat, 2 Nov 2024 14:09:50 +0100

1 Daily Problem, 2 Random

Diffstat:
AProblems/0354.cpp|+++++++++++++++++++++
AProblems/0355.cpp|++++++++++++++++++++++++++++++++++++++++++++
AProblems/2490.cpp|+++++++++++++++
MREADME.md|+++

4 files changed, 83 insertions(+), 0 deletions(-)

diff --git a/Problems/0354.cpp b/Problems/0354.cpp

@@ -0,0 +1,21 @@

class Solution {
public:
int maxEnvelopes(vector<vector<int>> &envelopes) const {
const int n = size(envelopes);
sort(begin(envelopes), end(envelopes),
[](const auto &a, const auto &b) { return a[0] != b[0] ? a[0] < b[0] : a[1] > b[1]; });
vector<int> res;
for (int i = 0; i < n; i++) {
const auto crnt = envelopes[i][1];
const auto it = lower_bound(begin(res), end(res), crnt);
if (it == end(res))
res.push_back(crnt);
else
*it = crnt;
}
return size(res);
}
};

diff --git a/Problems/0355.cpp b/Problems/0355.cpp

@@ -0,0 +1,44 @@

class Twitter {
vector<pair<int, int>> posts[501];
bool following[501][501] = {0};
int time = 0;
public:
Twitter() {
for (int i = 0; i <= 500; i++) {
following[i][i] = true;
}
}
void postTweet(int userId, int tweetId) { posts[userId].emplace_back(time++, tweetId); }
vector<int> getNewsFeed(int userId) {
using type_t = tuple<int, int, int>;
static const auto cmp = [](const type_t &a, const type_t &b) { return get<0>(a) < get<0>(b); };
priority_queue<type_t, vector<type_t>, decltype(cmp)> pq(cmp);
for (int i = 0; i <= 500; i++) {
if (!following[userId][i]) continue;
const int n = size(posts[i]);
if (n == 0) continue;
pq.emplace(posts[i][n - 1].first, i, n - 1);
if (size(pq) > 10) pq.pop();
}
vector<int> res;
while (!pq.empty() && size(res) < 10) {
const auto [time, user, idx] = pq.top();
pq.pop();
res.push_back(posts[user][idx].second);
if (idx - 1 >= 0) pq.emplace(posts[user][idx - 1].first, user, idx - 1);
}
return res;
}
void follow(int followerId, int followeeId) { following[followerId][followeeId] = true; }
void unfollow(int followerId, int followeeId) { following[followerId][followeeId] = false; }
};

diff --git a/Problems/2490.cpp b/Problems/2490.cpp

@@ -0,0 +1,15 @@

class Solution {
public:
bool isCircularSentence(const string &sentence) const {
char prev = sentence.back();
stringstream ss(sentence);
string word;
while (ss >> word) {
if (word.front() != prev) return false;
prev = word.back();
}
return true;
}
};

diff --git a/README.md b/README.md

@@ -319,6 +319,8 @@ reference and a base for solving problems.

| 0349 | Easy | [Intersection of Two Arrays](Problems/0349.cpp) |
| 0350 | Easy | [Intersection of Two Arrays II](Problems/0350.cpp) |
| 0352 | Hard | [Data Stream as Disjoint Intervals](Problems/0352.cpp) |
| 0354 | Hard | [Russian Doll Envelopes](Problems/0354.cpp) |
| 0355 | Medium | [Design Twitter](Problems/0355.cpp) |
| 0357 | Medium | [Count Numbers with Unique Digits](Problems/0357.cpp) |
| 0367 | Easy | [Valid Perfect Square](Problems/0367.cpp) |
| 0368 | Medium | [Largest Divisible Subset](Problems/0368.cpp) |

@@ -1288,6 +1290,7 @@ reference and a base for solving problems.

| 2485 | Easy | [Find the Pivot Integer](Problems/2485.cpp) |
| 2486 | Medium | [Append Characters to String to Make Subsequence](Problems/2486.cpp) |
| 2487 | Medium | [Remove Nodes From Linked List](Problems/2487.cpp) |
| 2490 | Easy | [Circular Sentence](Problems/2490.cpp) |
| 2491 | Medium | [Divide Players Into Teams of Equal Skill](Problems/2491.cpp) |
| 2492 | Medium | [Minimum Score of a Path Between Two Cities](Problems/2492.cpp) |
| 2497 | Medium | [Maximum Star Sum of a Graph](Problems/2497.cpp) |