leetcode

Solution to some Leetcode problems written in C++

git clone git://git.dimitrijedobrota.com/leetcode.git

commit	ff69f22747db5464711d5a3e8f8184a9fbe189c4
parent	e5acd3a1f703f9796029c62d754d875c27b92ae1
author	Dimitrije Dobrota <mail@dimitrijedobrota.com>
date	Thu, 24 Aug 2023 13:21:02 +0200

5 Random Problems

Diffstat:

A	Problems/0885.cpp	\|	++++++++++++++++++++++
A	Problems/1325.cpp	\|	++++++++++++++++++++++++++++++++
A	Problems/1418.cpp	\|	++++++++++++++++++++++++++++++++++
A	Problems/1448.cpp	\|	++++++++++++++++++++++
A	Problems/2023.cpp	\|	+++++++++++++++
M	README.md	\|	+++++

6 files changed, 130 insertions(+), 0 deletions(-)

diff --git a/Problems/0885.cpp b/Problems/0885.cpp

@@ -0,0 +1,22 @@

class Solution {

public:

vector<vector<int>> spiralMatrixIII(const int rows, const int cols, int x,

int y) {

static const int8_t offset_x[4] = {0, 1, 0, -1};

static const int8_t offset_y[4] = {1, 0, -1, 0};

vector<vector<int>> res;

res.reserve(rows * cols);

int dir = 0, cnt = 1, len = 1;

while (res.size() < rows * cols) {

for (int i = 0; i < len; i++) {

if (x >= 0 && x < rows && y >= 0 && y < cols) res.push_back({x, y});

x += offset_x[dir], y += offset_y[dir];

}

len += dir & 1;

dir = (dir + 1) & 0x3;

}

return res;

}

};

diff --git a/Problems/1325.cpp b/Problems/1325.cpp

@@ -0,0 +1,32 @@

class Solution {

public:

TreeNode *removeLeafNodes(TreeNode *root, int target) {

TreeNode dummy(-1, root, nullptr);

unordered_map<TreeNode *, TreeNode *> um = {

{root, &dummy}

};

stack<TreeNode *> st({root});

while (!st.empty()) {

TreeNode *root = st.top();

if (root->val < 0) {

st.pop();

root->val = -root->val;

if (!root->left && !root->right && root->val == target) {

TreeNode *parent = um[root];

(parent->left == root ? parent->left : parent->right) = nullptr;

}

continue;

}

root->val = -root->val;

if (root->left) {

um[root->left] = root;

st.push(root->left);

}

if (root->right) {

um[root->right] = root;

st.push(root->right);

}

return dummy.left;

}

};

diff --git a/Problems/1418.cpp b/Problems/1418.cpp

@@ -0,0 +1,34 @@

class Solution {

public:

vector<vector<string>> displayTable(vector<vector<string>> &orders) {

map<int, vector<string>> tables;

vector<vector<string>> res;

set<string> foods;

for (const auto &order : orders) {

tables[stoi(order[1])].push_back(order[2]);

foods.insert(order[2]);

}

unordered_map<string, int> pos;

int j = 1;

res.push_back({{"Table"}});

for (auto &food : foods) {

res[0].push_back(food);

pos[food] = j++;

}

for (auto &[table, foods] : tables) {

vector<int> row(res[0].size(), 0);

vector<string> rows;

rows.reserve(res[0].size());

for (const auto &food : foods) row[pos[food]]++;

row[0] = table;

for (int r : row) rows.push_back(to_string(r));

res.push_back(rows);

}

return res;

}

};

diff --git a/Problems/1448.cpp b/Problems/1448.cpp

@@ -0,0 +1,22 @@

class Solution {

public:

int goodNodes(TreeNode *root) {

queue<pair<TreeNode *, int>> q({

{root, INT_MIN}

});

int res = 0;

while (!q.empty()) {

const auto [root, maxi] = q.front();

q.pop();

if (root->val >= maxi) res++;

if (root->left) q.push({root->left, max(maxi, root->val)});

if (root->right) q.push({root->right, max(maxi, root->val)});

// For some reason it increases runtime and decreases memory usage

// Must be leetcode error...

root->left = root->right = nullptr;

}

return res;

}

};

diff --git a/Problems/2023.cpp b/Problems/2023.cpp

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

class Solution {

public:

int numOfPairs(const vector<string> &nums, const string target) {

unordered_map<string, int> um;

for (const auto &s : nums) um[s]++;

int res = 0;

for (int i = 0; i < target.size(); i++) {

const string s1 = target.substr(0, i);

const string s2 = target.substr(i);

res += (s1 != s2) ? um[s1] * um[s2] : um[s1] * (um[s1] - 1);

}

return res;

}

};

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

@@ -392,6 +392,7 @@ for solving problems.

| 0879 | Hard | [Profitable Schemes](Problems/0879.cpp) |

| 0881 | Medium | [Boats to Save People](Problems/0881.cpp) |

| 0884 | Easy | [Uncommon Words from Two Sentences](Problems/0884.cpp) |

| 0885 | Medium | [Spiral Matrix III](Problems/0885.cpp) |

| 0886 | Medium | [Possible Bipartition](Problems/0886.cpp) |

| 0890 | Medium | [Find and Replace Pattern](Problems/0890.cpp) |

| 0894 | Medium | [All Possible Full Binary Trees](Problems/0894.cpp) |

@@ -482,6 +483,7 @@ for solving problems.

| 1318 | Medium | [Minimum Flips to Make a OR b Equal to c](Problems/1318.cpp) |

| 1319 | Medium | [Number of Operations to Make Network Connected](Problems/1319.cpp) |

| 1323 | Easy | [Maximum 69 Number](Problems/1323.cpp) |

| 1325 | Medium | [Delete Leaves With a Given Value](Problems/1325.cpp) |

| 1329 | Medium | [Sort the Matrix Diagonally](Problems/1329.cpp) |

| 1334 | Medium | [Find the City With the Smallest Number of Neighbors at a Threshold Distance](Problems/1334.cpp) |

| 1337 | Easy | [The K Weakest Rows in a Matrix](Problems/1337.cpp) |

@@ -504,6 +506,7 @@ for solving problems.

| 1406 | Hard | [Stone Game III](Problems/1406.cpp) |

| 1409 | Medium | [Queries on a Permutation With Key](Problems/1409.cpp) |

| 1416 | Hard | [Restore The Array](Problems/1416.cpp) |

| 1418 | Medium | [Display Table of Food Orders in a Restaurant](Problems/1418.cpp) |

| 1425 | Hard | [Constrained Subsequence Sum](Problems/1425.cpp) |

| 1431 | Easy | [Kids With the Greatest Number of Candies](Problems/1431.cpp) |

| 1436 | Easy | [Destination City](Problems/1436.cpp) |

@@ -511,6 +514,7 @@ for solving problems.

| 1442 | Medium | [Count Triplets That Can Form Two Arrays of Equal XOR](Problems/1442.cpp) |

| 1443 | Medium | [Minimum Time to Collect All Apples in a Tree](Problems/1443.cpp) |

| 1444 | Hard | [Number of Ways of Cutting a Pizza](Problems/1444.cpp) |

| 1448 | Medium | [Count Good Nodes in Binary Tree](Problems/1448.cpp) |

| 1456 | Medium | [Maximum Number of Vowels in a Substring of Given Length](Problems/1456.cpp) |

| 1462 | Medium | [Course Schedule IV](Problems/1462.cpp) |

| 1466 | Medium | [Reorder Routes to Make All Paths Lead to the City Zero](Problems/1466.cpp) |

@@ -586,6 +590,7 @@ for solving problems.

| 1971 | Easy | [Find if Path Exists in Graph](Problems/1971.cpp) |

| 1976 | Medium | [Number of Ways to Arrive at Destination](Problems/1976.cpp) |

| 1991 | Easy | [Find the Middle Index in Array](Problems/1991.cpp) |

| 2023 | Medium | [Number of Pairs of Strings With Concatenation Equal to Target](Problems/2023.cpp) |

| 2024 | Medium | [Maximize the Confusion of an Exam](Problems/2024.cpp) |

| 2039 | Medium | [The Time When the Network Becomes Idle](Problems/2039.cpp) |

| 2044 | Medium | [Count Number of Maximum Bitwise-OR Subsets](Problems/2044.cpp) |