leetcode

Add some daily problems

5 files changed, 138 insertions(+), 0 deletions(-)

diff --git a/ Problems/0124.cpp b/ Problems/0124.cpp

@@ -0,0 +1,41 @@

class Solution {

public:

int maxPathSum(TreeNode *root) {

if (!root) return 0;

int res = INT_MIN;

unordered_set<TreeNode *> us;

stack<TreeNode *> st;

while (root) {

st.push(root);

root = root->left;

}

while (!st.empty()) {

TreeNode *root = st.top();

st.pop();

if (us.find(root) == us.end()) {

st.push(root);

us.insert(root);

root = root->right;

while (root) {

st.push(root);

root = root->left;

}

} else {

int opt = 0, sum = 0;

if (root->left) {

opt = max(opt, root->left->val), sum += root->left->val;

};

if (root->right) {

opt = max(opt, root->right->val), sum += root->right->val;

};

res = max(res, root->val + sum);

root->val = max(root->val, root->val + opt);

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

continue;

}

}

return res;

}

};

diff --git a/ Problems/0938.cpp b/ Problems/0938.cpp

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

class Solution {

public:

Solution() {

ios_base::sync_with_stdio(false);

cin.tie(nullptr);

cout.tie(nullptr);

}

int rangeSumBST(TreeNode *root, int low, int high) {

int sum = 0;

stack<TreeNode *> st;

st.push(root);

while (!st.empty()) {

TreeNode *root = st.top();

st.pop();

if (root->val >= low && root->val <= high) sum += root->val;

if (root->left && root->val > low) st.push(root->left);

if (root->right && root->val < high) st.push(root->right);

}

return sum;

}

};

diff --git a/ Problems/1026.cpp b/ Problems/1026.cpp

@@ -0,0 +1,30 @@

class Solution {

public:

int maxAncestorDiff(TreeNode *root) {

if (!root) return 0;

int res = 0;

stack<pair<TreeNode *, pair<int, int>>> st;

st.push({

root, {root->val, root->val}

});

while (!st.empty()) {

TreeNode *root = st.top().first;

int maxi = st.top().second.first;

int mini = st.top().second.second;

st.pop();

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

res = max(res, abs(mini - root->val));

if (root->left)

st.push({

root->left,

{max(maxi, root->left->val), min(mini, root->left->val)}

});

if (root->right)

st.push({

root->right,

{max(maxi, root->right->val), min(mini, root->right->val)}

});

}

return res;

}

};

diff --git a/ Problems/1339.cpp b/ Problems/1339.cpp

@@ -0,0 +1,41 @@

class Solution {

public:

int maxProduct(TreeNode *root) {

if (!root) return 0;

const unsigned int M = 1000000007;

stack<TreeNode *> st;

st.push(root);

unordered_set<TreeNode *> visited;

while (!st.empty()) {

TreeNode *root = st.top();

st.pop();

if (visited.find(root) != visited.end()) {

if (root->left) root->val += root->left->val;

if (root->right) root->val += root->right->val;

root->val %= M;

continue;

}

st.push(root);

visited.insert(root);

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

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

}

long long res = 0ll;

int total = root->val;

st.push(root);

while (!st.empty()) {

TreeNode *root = st.top();

st.pop();

if (root->left) {

res = max(res, 1ll * root->left->val * (total - root->left->val));

st.push(root->left);

}

if (root->right) {

res = max(res, 1ll * root->right->val * (total - root->right->val));

st.push(root->right);

}

}

return res % M;

}

};

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

@@ -48,6 +48,7 @@ if you have any questions. | 0118 | Easy | [Pascal's Triangle](Problems/0118.cpp) | | 0119 | Easy | [Pascal's Triangle II](Problems/0119.cpp) | | 0121 | Easy | [Best Time to Buy and Sell Stock](Problems/0121.cpp) |

| 0124 | Hard | [Binary Tree Maximum Path Sum](Problems/0124.cpp) |

| 0133 | Medium | [Clone Graph](Problems/0133.cpp) | | 0138 | Medium | [Copy List with Random Pointer](Problems/0138.cpp) | | 0141 | Easy | [Linked List Cycle](Problems/0141.cpp) |

@@ -126,6 +127,7 @@ if you have any questions. | 0901 | Medium | [Online Stock Span](Problems/0901.cpp) | | 0905 | Easy | [Sort Array By Parity](Problems/0905.cpp) | | 0933 | Easy | [Number of Recent Calls](Problems/0933.cpp) |

| 0938 | Easy | [Range Sum of BST](Problems/0938.cpp) |

| 0941 | Easy | [Valid Mountain Array](Problems/0941.cpp) | | 0947 | Medium | [Most Stones Removed with Same Row or Column](Problems/0947.cpp) | | 0950 | Medium | [Reveal Cards In Increasing Order](Problems/0950.cpp) |

@@ -137,6 +139,7 @@ if you have any questions. | 0997 | Easy | [Find the Town Judge](Problems/0997.cpp) | | 1019 | Medium | [Next Greater Node In Linked List](Problems/1019.cpp) | | 1022 | Easy | [Sum of Root To Leaf Binary Numbers](Problems/1022.cpp) |

| 1026 | Medium | [Maximum Difference Between Node and Ancestor](Problems/1026.cpp) |

| 1047 | Easy | [Remove All Adjacent Duplicates In String](Problems/1047.cpp) | | 1051 | Easy | [Height Checker](Problems/1051.cpp) | | 1089 | Easy | [Duplicate Zeros](Problems/1089.cpp) |

@@ -148,6 +151,7 @@ if you have any questions. | 1319 | Medium | [Number of Operations to Make Network Connected](Problems/1319.cpp) | | 1323 | Easy | [Maximum 69 Number](Problems/1323.cpp) | | 1337 | Easy | [The K Weakest Rows in a Matrix](Problems/1337.cpp) |

| 1339 | Medium | [Maximum Product of Splitted Binary Tree](Problems/1339.cpp) |

| 1342 | Easy | [Number of Steps to Reduce a Number to Zero](Problems/1342.cpp) | | 1346 | Easy | [Check if N and Its Double Exist](Problems/1346.cpp) | | 1367 | Medium | [Linked List in Binary Tree ](Problems/1367.cpp) |

@@ -185,6 +189,7 @@ if you have any questions. | 2466 | Medium | [Count Ways To Build Good Strings](Problems/2466.cpp) | | 2467 | Medium | [Most Profitable Path in a Tree](Problems/2467.cpp) | | 2469 | Hard | [Find Median from Data Stream](Problems/0295.cpp) |

## DNF