add some code

Author: huxiaoman7

python/34_FindFirstandLastPositionofElementinSortedArray.py

@@ -7,16 +7,32 @@
 # @E-mail  : charlotte77_hu@sina.com
 
 
-class Solution(object):
+class Solution:
 
+    def searchRange(self, nums, target):
+        left_idx = self.extreme_insertion_index(nums, target, True)
 
+        if left_idx == len(nums) or nums[left_idx] != target:
+            return [-1, -1]
 
+        return [left_idx, self.extreme_insertion_index(nums, target, False)-1]
 
 
+    def extreme_insertion_index(self, nums, target, left):
+        lo = 0
+        hi = len(nums)
 
+        while lo < hi:
+            mid = (lo + hi) // 2
+            if nums[mid] > target or (left and target == nums[mid]):
+                hi = mid
+            else:
+                lo = mid+1
+
+        return lo
 
 
 
 if __name__=='__main__':
     s = Solution()
-    print
+    print s.searchRange([5,7,7,8,8,10],8)

python/35_SearchInsertPosition.py

@@ -8,15 +8,22 @@
 
 
 class Solution(object):
-
-
-
-
-
-
-
+    def searchInsert(self, nums, target):
+        """
+        :type nums: List[int]
+        :type target: int
+        :rtype: int
+        """
+        low, high = 0, len(nums)
+        while low < high:
+            mid = (low+high)/2
+            if nums[mid] >= target:
+                high = mid
+            else:
+                low = mid + 1
+        return low
 
 
 if __name__=='__main__':
     s = Solution()
-    print
+    print s.searchInsert([1,3,5,6],5)

python/36_ValidSudoku.py

@@ -6,17 +6,71 @@
 # @Package : LeetCode
 # @E-mail  : charlotte77_hu@sina.com
 
+class Solution1(object):
+    def isValidSudoku(self, board):
+        """
+        :type board: List[List[str]]
+        :rtype: bool
+        """
+        ## 方法一：按照三个规则全部检查一遍
+        for i in range(9):
+            if not self.isValidNine(board[i]):
+                return False
+            col = [c[i] for c in board]
+            if not self.isValidNine(col):
+                return False
 
-class Solution(object):
+        for i in [0,3,6]:
+            for j in [0,3,6]:
+                block = [board[s][t] for s in [i,i+1,i+2] for t in [j,j+1,j+2]]
+                if not self.isValidNine(block):
+                    return False
+        return True
 
+    def isValidNine(self,row):
+        map = {}
+        for c in row:
+            if c!= '.':
+                if c in map:
+                    return False
+                else:
+                    map[c] = True
+        return True
 
+# 方法二：用三个矩阵来分别检查三个规则是否有重复数字，譬如row、col、block分别检查行、列、块是否有重复数字
+class Solution2(object):
+    def isValidSudoku(self,board):
+        row = [[False for i in range(9)] for j in range(9)]
+        col = [[False for i in range(9)] for j in range(9)]
+        block = [[False for i in range(9)] for j in range(9)]
+        for i in range(9):
+            for j in range(9):
+                if board[i][j] != '.':
+                    num = int(board[i][j])-1
+                    k=i/3*3 +j/3
+                    if row[i][num] or col[j][num] or block[k][num]:
+                        return False
+                    row[i][num] = col[j][num] =block[k][num] =True
+        return True
 
 
+# 方法三：记录所有出现过的行、列、块的数字及相应的位置，最后判断是否有重复。用set操作精简代码
+class Solution3(object):
+    def isValidSudoku(self,board):
+        seen=[]
+        for i,row in enumerate(board):
+            for j,c in enumerate(row):
+                # print j,c
+                if c !='.':
+                    seen += [(c,j),(i,c),(i/3,j/3,c)]
+        # print seen
+        return len(seen) == len(set(seen))
+
 
 
 
 
 
 if __name__=='__main__':
-    s = Solution()
-    print
+    s = Solution3()
+    print s.isValidSudoku([["5","3",".",".","7",".",".",".","."],["6",".",".","1","9","5",".",".","."],[".","9","8",".",".",".",".","6","."],["8",".",".",".","6",".",".",".","3"],["4",".",".","8",".","3",".",".","1"],["7",".",".",".","2",".",".",".","6"],[".","6",".",".",".",".","2","8","."],[".",".",".","4","1","9",".",".","5"],[".",".",".",".","8",".",".","7","9"]])

python/37_SodukoSolver.py

@@ -7,16 +7,60 @@
 # @E-mail  : charlotte77_hu@sina.com
 
 
-class Solution(object):
+class Solution:
 
+    def solveSudoku(self, board):
+        self.board = board
+        self.solve()
 
+    def findUnassigned(self):
+        for row in range(9):
+            for col in range(9):
+                if self.board[row][col] == ".":
+                    return row, col
+        return -1, -1
 
+    def solve(self):
+        row, col = self.findUnassigned()
+        if row == -1 and col == -1:
+            return True
+        for num in ["1","2","3","4","5","6","7","8","9"]:
+            if self.isSafe(row, col, num):
+                self.board[row][col] = num
+                if self.solve():
+                    return True
+                self.board[row][col] = "."
+        return False
 
+    def isSafe(self, row, col, ch):
+        boxrow = row - row%3
+        boxcol = col - col%3
+        if self.checkrow(row,ch) and self.checkcol(col,ch) and self.checksquare(boxrow, boxcol, ch):
+            return True
+        return False
 
+    def checkrow(self, row, ch):
+        for col in range(9):
+            if self.board[row][col] == ch:
+                return False
+        return True
+
+    def checkcol(self, col, ch):
+        for row in range(9):
+            if self.board[row][col] == ch:
+                return False
+        return True
+
+    def checksquare(self, row, col, ch):
+        for r in range(row, row+3):
+            for c in range(col, col+3):
+                if self.board[r][c] == ch:
+                    return False
+        return True
 
 
 
 
 if __name__=='__main__':
     s = Solution()
-    print
+    print s.solveSudoku([["5","3",".",".","7",".",".",".","."],["6",".",".","1","9","5",".",".","."],[".","9","8",".",".",".",".","6","."],["8",".",".",".","6",".",".",".","3"],["4",".",".","8",".","3",".",".","1"],["7",".",".",".","2",".",".",".","6"],[".","6",".",".",".",".","2","8","."],[".",".",".","4","1","9",".",".","5"],[".",".",".",".","8",".",".","7","9"]])

python/38_CountandSay.py

@@ -8,8 +8,24 @@
 
 
 class Solution(object):
-
-
+    def countAndSay(self, n):
+        """
+        :type n: int
+        :rtype: str
+        """
+        s = '1'
+        for _ in range(n-1):
+            let, temp, count = s[0], '', 0
+            for l in s:
+                if let == l:
+                    count += 1
+                else:
+                    temp += str(count)+let
+                    let = l
+                    count = 1
+            temp += str(count)+let
+            s = temp
+        return s
 
 
 
@@ -19,4 +35,4 @@ class Solution(object):
 
 if __name__=='__main__':
     s = Solution()
-    print
+    print s.countAndSay(11)

python/39_CombinationSum.py

@@ -8,8 +8,31 @@
 
 
 class Solution(object):
+    def combinationSum(self, candidates, target):
+        """
+        :type candidates: List[int]
+        :type target: int
+        :rtype: List[List[int]]
+        """
+        # 方法一：DFS
+        self.resList = []
+        candidates = sorted(candidates)
+        self.dfs(candidates,[],target,0)
+        return self.resList
 
-
+    def dfs(self,candidates,sublist,target,last):
+        if target == 0:
+            self.resList.append(sublist[:])
+        if target < candidates[0]:
+            return
+        for n in candidates:
+            if n >target:
+                return
+            if n<last:
+                continue
+            sublist.append(n)
+            self.dfs(candidates,sublist,target-n,n)
+            sublist.pop()
 
 
 
@@ -19,4 +42,4 @@ class Solution(object):
 
 if __name__=='__main__':
     s = Solution()
-    print
+    print s.combinationSum([2,3,6,7],7)

python/40_CombinationSumII.py

@@ -8,8 +8,29 @@
 
 
 class Solution(object):
+    def combinationSum2(self, candidates, target):
+        """
+        :type candidates: List[int]
+        :type target: int
+        :rtype: List[List[int]]
+        """
+        #方法一：DFS
+        candidates.sort()
+        print candidates
+        res=[]
+        self.dfs(candidates, target, 0, res, [])
+        return res
 
-
+    def dfs(self, nums, target,index,res,path):
+        if target < 0:
+            return
+        elif target == 0:
+            res.append(path)
+            return
+        for i in xrange(index, len(nums)):
+            if i > index and nums[i] == nums[i-1]:
+                continue
+            self.dfs(nums,target-nums[i],i+1,res,path+[nums[i]])
 
 
 
@@ -19,4 +40,4 @@ class Solution(object):
 
 if __name__=='__main__':
     s = Solution()
-    print
+    print s.combinationSum2([10,1,2,7,6,1,5],8)

python/41_FirstMissingPositive.py

@@ -8,15 +8,28 @@
 
 
 class Solution(object):
+    def firstMissingPositive(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: int
+        """
 
-
-
-
+        nums.append(0)
+        n = len(nums)
+        for i in range(len(nums)):
+            if nums[i]<0 or nums[i]>=n:
+                nums[i]=0
+        for i in range(len(nums)):
+            nums[nums[i]%n]+=n
+        for i in range(1,len(nums)):
+            if nums[i]/n==0:
+                return i
+        return n
 
 
 
 
 
 if __name__=='__main__':
     s = Solution()
-    print
+    print s.firstMissingPositive([1,2,0])

python/42_TrappingRainWater.py

@@ -6,17 +6,24 @@
 # @Package : LeetCode
 # @E-mail  : charlotte77_hu@sina.com
 
-
-class Solution(object):
-
-
-
-
-
-
+class Solution:
+    # @param {integer[]} height
+    # @return {integer}
+    def trap(self, height):
+        n = len(height)
+        l, r, water, minHeight = 0, n - 1, 0, 0
+        while l < r:
+            while l < r and height[l] <= minHeight:
+                water += minHeight - height[l]
+                l += 1
+            while r > l and height[r] <= minHeight:
+                water += minHeight - height[r]
+                r -= 1
+            minHeight = min(height[l], height[r])
+        return water
 
 
 
 if __name__=='__main__':
     s = Solution()
-    print
+    print s.trap([0,1,0,2,1,0,1,3,2,1,2,1])