7 problems solved.

lintcoder · lintcoder · commit 4119a4155b3a · 2018-09-15T20:45:41.000+08:00
diff --git a/src/700.cpp b/src/700.cpp
@@ -0,0 +1,17 @@
+TreeNode* searchBST(TreeNode* root, int val) {
+     if (root == nullptr)
+     return root;
+
+     TreeNode* node = root;
+     while (node != nullptr)
+     {
+     	if (node->val == val)
+     		return node;
+     	else if (node->val < val)
+     		node = node->right;
+     	else
+     		node = node->left;
+     }
+
+     return nullptr;
+    }
diff --git a/src/709.cpp b/src/709.cpp
@@ -0,0 +1,5 @@
+string toLowerCase(string str) {
+        transform(str.begin(), str.end(), str.begin(), ::tolower);
+        
+        return str;
+    }
diff --git a/src/841.cpp b/src/841.cpp
@@ -0,0 +1,30 @@
+bool canVisitAllRooms(vector<vector<int>>& rooms) {
+        int N = rooms.size();
+        if (N == 1)
+        	return true;
+
+        int* number = new int[N];
+        memset(number, 0, N*sizeof(int));
+        number[0] = 1;
+        int ct = 1;
+
+        deque<int> dq(rooms[0].begin(), rooms[0].end());
+
+        int len = dq.size();
+        while (len != 0)
+        {
+        	for (int i = 0; i < len; ++i)
+        	{
+        		if (number[dq[i]] == 0)
+        		{
+        			dq.insert(dq.end(), rooms[dq[i]].begin(), rooms[dq[i]].end());
+        			number[dq[i]] = 1;
+        			++ct;
+        		}
+        	}
+        	dq.erase(dq.begin(), dq.begin() + len);
+        	len = dq.size();
+        }
+        delete []number;
+        return ct == N;
+    }
diff --git a/src/867.cpp b/src/867.cpp
@@ -0,0 +1,17 @@
+vector<vector<int>> transpose(vector<vector<int>>& A) {
+        int row = A.size();
+        if (row == 0)
+        	return A;
+        int col = A[0].size();
+
+        vector<vector<int>> res(col, vector<int>(row, 0));
+    	for (int i = 0; i < row; ++i)
+    	{
+    		for (int j = 0; j < col; ++j)
+    		{
+    			res[j][i] = A[i][j];
+    		}
+    	}
+
+    	return res;
+    }
diff --git a/src/872.cpp b/src/872.cpp
@@ -0,0 +1,37 @@
+bool leafSimilar(TreeNode* root1, TreeNode* root2) {
+     if (root1 == nullptr && root2 == nullptr)
+     return true;
+
+     if (root1 == nullptr || root2 == nullptr)
+     return false;
+
+     vector<int> leaf1, leaf2;
+     getLeaf(root1, leaf1);
+     getLeaf(root2, leaf2);
+
+     int len1 = leaf1.size();
+     int len2 = leaf2.size();
+     if (len1 != len2)
+     return false;
+
+     for (int i = 0; i < len1; ++i)
+     {
+     	if (leaf1[i] != leaf2[i])
+     		return false;
+     }
+
+     return true;
+    }
+
+void getLeaf(TreeNode* node, vector<int>& vec)
+{
+	if (node->left == nullptr && node->right == nullptr)
+		vec.push_back(node->val);
+	else
+	{
+		if (node->left != nullptr)
+			getLeaf(node->left, vec);
+		if (node->right != nullptr)
+			getLeaf(node->right, vec);
+	}
+}
diff --git a/src/876.cpp b/src/876.cpp
@@ -0,0 +1,22 @@
+ListNode* middleNode(ListNode* head) {
+        if (head == nullptr || head->next == nullptr)
+        	return head;
+
+        int len = 0;
+        ListNode* node = head;
+        while (node != nullptr)
+        {
+        	node = node->next;
+        	++len;
+        }
+        int pos = len/2;
+        int i = 0;
+        node = head;
+        while (i != pos)
+        {
+        	node = node->next;
+        	++i;
+        }
+
+        return node;
+    }
diff --git a/src/896.cpp b/src/896.cpp
@@ -0,0 +1,20 @@
+bool isMonotonic(vector<int>& A) {
+     int len = A.size();
+     if (len == 1)
+     return true;
+
+ 	 int pos = 1;
+ 	 while (A[pos] == A[0])
+ 	 	++pos;
+ 	 if (pos == len)
+ 	 	return true;
+
+     bool flag = A[0] <= A[pos] ? true : false;
+     for (int i = pos; i < len-1; ++i)
+     {
+     	if ((flag && A[i] > A[i+1]) || (!flag && A[i] < A[i+1]))
+     		return false;
+     }
+
+     return true;
+    }
