leetcode

5 Random Problems

6 files changed, 115 insertions(+), 0 deletions(-)

diff --git a/ Problems/0515.cpp b/ Problems/0515.cpp

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

class Solution {

public:

vector<int> largestValues(const TreeNode *root) {

if (!root) return {};

vector<int> res;

queue<const TreeNode *> q({root});

while (!q.empty()) {

int maxi = INT_MIN;

for (int k = q.size(); k > 0; k--) {

const TreeNode *root = q.front();

q.pop();

maxi = max(maxi, root->val);

if (root->left) q.push(root->left);

if (root->right) q.push(root->right);

}

res.push_back(maxi);

}

return res;

}

};

diff --git a/ Problems/0856.cpp b/ Problems/0856.cpp

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

// Stack solution

class Solution {

public:

int scoreOfParentheses(const string &s) {

stack<int> st;

int score = 0;

for (const char c : s) {

if (c == '(')

st.push(score), score = 0;

else {

score = score ? 2 * score : 1;

score += st.top();

st.pop();

}

}

return score;

}

};

// O(1) memory solution

class Solution {

public:

int scoreOfParentheses(const string &s) {

int res = 0, l = 0;

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

l += s[i] == '(' ? 1 : -1;

if (s[i] == ')' && s[i - 1] == '(') res += 1 << l;

}

return res;

}

};

diff --git a/ Problems/0919.cpp b/ Problems/0919.cpp

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

class CBTInserter {

TreeNode *root = nullptr;

queue<TreeNode *> q;

public:

CBTInserter(TreeNode *root) : root(root), q({root}) {}

TreeNode *get_root() { return root; }

int insert(int val) {

TreeNode *node = new TreeNode(val);

while (!q.empty()) {

TreeNode *root = q.front();

if (root->left)

q.push(root->left);

else {

root->left = node;

q.push(root->left);

return root->val;

}

q.pop();

if (root->right)

q.push(root->right);

else {

root->right = node;

q.push(root->right);

return root->val;

}

}

return -1;

}

};

diff --git a/ Problems/1358.cpp b/ Problems/1358.cpp

@@ -0,0 +1,14 @@

class Solution {

public:

int numberOfSubstrings(const string &s) {

int st[3] = {0}, count = 0, res = 0, left = 0;

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

if (!st[s[i] - 'a']++) count++;

while (count == 3) {

res += s.size() - i;

if (!--st[s[left++] - 'a']) count--;

}

}

return res;

}

};

diff --git a/ Problems/2486.cpp b/ Problems/2486.cpp

@@ -0,0 +1,9 @@

class Solution {

public:

int appendCharacters(const string &s, const string &t) {

int j = 0;

for (int i = 0; i < s.size() && j < t.size(); i++)

if (s[i] == t[j]) j++;

return t.size() - j;

}

};

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

@@ -310,6 +310,7 @@ for solving problems. | 0508 | Medium | [Most Frequent Subtree Sum](Problems/0508.cpp) | | 0509 | Easy | [Fibonacci Number](Problems/0509.cpp) | | 0513 | Medium | [Find Bottom Left Tree Value](Problems/0513.cpp) |

| 0515 | Medium | [Find Largest Value in Each Tree Row](Problems/0515.cpp) |

| 0516 | Medium | [Longest Palindromic Subsequence](Problems/0516.cpp) | | 0518 | Medium | [Coin Change II](Problems/0518.cpp) | | 0520 | Easy | [Detect Capital](Problems/0520.cpp) |

@@ -400,6 +401,7 @@ for solving problems. | 0851 | Medium | [Loud and Rich](Problems/0851.cpp) | | 0852 | Medium | [Peak Index in a Mountain Array](Problems/0852.cpp) | | 0853 | Medium | [Car Fleet](Problems/0853.cpp) |

| 0856 | Medium | [Score of Parentheses](Problems/0856.cpp) |

| 0859 | Easy | [Buddy Strings](Problems/0859.cpp) | | 0861 | Medium | [Score After Flipping Matrix](Problems/0861.cpp) | | 0863 | Medium | [All Nodes Distance K in Binary Tree](Problems/0863.cpp) |

@@ -426,6 +428,7 @@ for solving problems. | 0912 | Medium | [Sort an Array](Problems/0912.cpp) | | 0915 | Medium | [Partition Array into Disjoint Intervals](Problems/0915.cpp) | | 0918 | Medium | [Maximum Sum Circular Subarray](Problems/0918.cpp) |

| 0919 | Medium | [Complete Binary Tree Inserter](Problems/0919.cpp) |

| 0920 | Hard | [Number of Music Playlists](Problems/0920.cpp) | | 0921 | Medium | [Minimum Add to Make Parentheses Valid](Problems/0921.cpp) | | 0926 | Medium | [Flip String to Monotone Increasing](Problems/0926.cpp) |

@@ -539,6 +542,7 @@ for solving problems. | 1347 | Medium | [Minimum Number of Steps to Make Two Strings Anagram](Problems/1347.cpp) | | 1351 | Easy | [Count Negative Numbers in a Sorted Matrix](Problems/1351.cpp) | | 1357 | Medium | [Apply Discount Every n Orders](Problems/1357.cpp) |

| 1358 | Medium | [Number of Substrings Containing All Three Characters](Problems/1358.cpp) |

| 1359 | Hard | [Count All Valid Pickup and Delivery Options](Problems/1359.cpp) | | 1361 | Medium | [Validate Binary Tree Nodes](Problems/1361.cpp) | | 1367 | Medium | [Linked List in Binary Tree ](Problems/1367.cpp) |

@@ -751,6 +755,7 @@ for solving problems. | 2477 | Medium | [Minimum Fuel Cost to Report to the Capital](Problems/2477.cpp) | | 2482 | Medium | [Difference Between Ones and Zeros in Row and Column](Problems/2482.cpp) | | 2483 | Medium | [Minimum Penalty for a Shop](Problems/2483.cpp) |

| 2486 | Medium | [Append Characters to String to Make Subsequence](Problems/2486.cpp) |

| 2487 | Medium | [Remove Nodes From Linked List](Problems/2487.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) |