leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
Log | Files | Refs | README | LICENSE |
commitc800b121c4af0d519385d2ed538e63787469448b
parent5684438eea23a066e6c3d856cfa1725a3c1588df
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateSat, 4 Feb 2023 12:17:07 +0100

LeetCode 75 I: Day 15 FINISH

Diffstat:
AProblems/0692.cpp|++++++++++++++++++++++++++++++++++++++++++++++
AProblems/1046.cpp|+++++++++++++++++++
MREADME.md|++

3 files changed, 67 insertions(+), 0 deletions(-)

diff --git a/Problems/0692.cpp b/Problems/0692.cpp

@@ -0,0 +1,46 @@

// sort: O(nlogn)
class Solution {
public:
vector<string> topKFrequent(const vector<string> &words, int k) {
unordered_map<string, int> um;
for (const auto &w : words) um[w]++;
vector<pair<int, string>> vec(um.size());
vector<string> res(k);
int count = 0;
for (const auto &[k, v] : um) vec[count++] = {-v, k};
sort(vec.begin(), vec.end());
for (int i = 0; i < k; i++) res[i] = vec[i].second;
return res;
}
};
// heap: O(nlogk)
class Solution {
typedef pair<string, int> psi;
static constexpr const auto cmp = [](const psi &p1, const psi &p2) {
if (p1.second == p2.second) return p1.first < p2.first;
return p1.second > p2.second;
};
public:
vector<string> topKFrequent(const vector<string> &words, int k) {
unordered_map<string, int> um;
for (const auto &w : words) um[w]++;
priority_queue<psi, vector<psi>, decltype(cmp)> pq(cmp);
vector<string> res(k);
for (auto it : um) {
pq.push(it);
if (pq.size() > k) pq.pop();
}
int count = k - 1;
while (!pq.empty()) res[count--] = pq.top().first, pq.pop();
return res;
}
};

diff --git a/Problems/1046.cpp b/Problems/1046.cpp

@@ -0,0 +1,19 @@

class Solution {
public:
int lastStoneWeight(vector<int> &stones) {
int n = stones.size();
make_heap(stones.begin(), stones.end());
while (stones.size() > 1) {
int x, y;
pop_heap(stones.begin(), stones.end());
y = stones.back(), stones.pop_back();
pop_heap(stones.begin(), stones.end());
x = stones.back(), stones.pop_back();
if (x != y) {
stones.push_back(y - x);
push_heap(stones.begin(), stones.end());
}
}
return !stones.empty() ? stones.back() : 0;
}
};

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

@@ -229,6 +229,7 @@ for solving problems.

| 0669 | Medium | [Trim a Binary Search Tree](Problems/0669.cpp) |
| 0671 | Easy | [Second Minimum Node In a Binary Tree](Problems/0671.cpp) |
| 0684 | Medium | [Redundant Connection](Problems/0684.cpp) |
| 0692 | Medium | [Top K Frequent Words](Problems/0692.cpp) |
| 0695 | Medium | [Max Area of Island](Problems/0695.cpp) |
| 0700 | Easy | [Search in a Binary Search Tree](Problems/0700.cpp) |
| 0701 | Medium | [Insert into a Binary Search Tree](Problems/0701.cpp) |

@@ -290,6 +291,7 @@ for solving problems.

| 1026 | Medium | [Maximum Difference Between Node and Ancestor](Problems/1026.cpp) |
| 1038 | Medium | [Binary Search Tree to Greater Sum Tree](Problems/1038.cpp) |
| 1042 | Medium | [Flower Planting With No Adjacent](Problems/1042.cpp) |
| 1046 | Easy | [Last Stone Weight](Problems/1046.cpp) |
| 1047 | Easy | [Remove All Adjacent Duplicates In String](Problems/1047.cpp) |
| 1051 | Easy | [Height Checker](Problems/1051.cpp) |
| 1061 | Medium | [Lexicographically Smallest Equivalent String](Problems/1061.cpp) |