12.7

Author: huangyt39

123.py

@@ -0,0 +1,57 @@
+class Solution:
+    """
+    @param board: A list of lists of character
+    @param word: A string
+    @return: A boolean
+    """
+    def exist(self, board, word):
+        # write your code here
+        if len(board) == 0 or len(board[0]) == 0:
+            return False
+        if len(word) == 0:
+            return True
+        
+        cols, rows = len(board), len(board[0])
+        used = [[0]*rows for i in range(cols)]
+        # print(used)
+        for i in range(cols):
+            for j in range(rows):
+                if Solution.findWord(1, board, word, cols, rows, i, j, used):
+                    return True
+        
+        return False
+    
+    def findWord(self, board, word, cols, rows, indexi, indexj, used):
+        if len(word) == 0:
+            return True
+        if indexi < 0 or indexi >= cols:
+            return False
+        if indexj < 0 or indexj >= rows:
+            return False
+        # print(board[indexi][indexj])
+        # print("word:", word, word[1:])
+        # print(used[indexi][indexj] == 0, indexi, indexj)
+        # print(board[indexi][indexj] == word[0])
+        # print(used)
+        if used[indexi][indexj] == 1 or board[indexi][indexj] != word[0]:
+            return False
+        
+        used[indexi][indexj] = 1
+
+        res = Solution.findWord(1, board, word[1:], cols, rows, indexi-1, indexj, used) or Solution.findWord(1, board, word[1:], cols, rows, indexi+1, indexj, used) or Solution.findWord(1, board, word[1:], cols, rows, indexi, indexj+1, used) or Solution.findWord(1, board, word[1:], cols, rows, indexi, indexj-1, used)
+
+        if res == False:
+            used[indexi][indexj] = 0
+        return res
+
+arr = [
+
+  "ABCE",
+
+  "SFCS",
+
+  "ADEE"
+
+]
+word = "ABCCE"
+print(Solution.exist(1, arr, word))

165.cpp

@@ -0,0 +1,68 @@
+
+Definition of singly-linked-list:
+class ListNode {
+    public:
+        int val;
+        ListNode *next;
+        ListNode(int val) {
+        this->val = val;
+        this->next = NULL;
+    }
+}
+
+
+class Solution {
+public:
+    /**
+     * @param l1: ListNode l1 is the head of the linked list
+     * @param l2: ListNode l2 is the head of the linked list
+     * @return: ListNode head of linked list
+     */
+    ListNode * mergeTwoLists(ListNode * l1, ListNode * l2) {
+        // write your code here
+        if(l1 == NULL){
+            return l2;
+        }
+        if(l2 == NULL){
+            return l1;
+        }
+
+        ListNode *tmp = NULL;
+        ListNode *head = NULL;
+        if(l1->val < l2->val){
+            head = new ListNode(l1->val);
+            l1 = l1->next;
+        }
+        else{
+            head = new ListNode(l2->val);
+            l2 = l2->next;
+        }
+        ListNode *front = head;
+        while(l1 != NULL && l2 != NULL){
+            if(l1->val < l2->val){
+                tmp = new ListNode(l1->val);
+                l1 = l1->next;
+            }
+            else{
+                tmp = new ListNode(l2->val);
+                l2 = l2->next;
+            }
+            front->next = tmp;
+            front = tmp;
+        }
+        while(l1 != NULL){
+            tmp = new ListNode(l1->val);
+            front->next = tmp;
+            front = tmp;
+            l1 = l1->next;
+        }
+        while(l2 != NULL){
+            tmp = new ListNode(l2->val);
+            front->next = tmp;
+            front = tmp;
+            l2 = l2->next;
+        }
+
+        return head;
+    }
+};