fix:二分查找

999-算法思想/01-二分查找/problem_solving_01.py

+"""
+二分查找基础版
+"""
+
+from typing import List
+
+class Solution:
+    def distributeCoins(self, nums: List[int], target: int) -> int:
+        """
+        二分查找基础版
+        :param nums:
+        :param target:
+        :return:
+        """
+        left, right = 0, len(nums) - 1
+        while left <= right:
+            mid = (left + right) >> 1
+            if nums[mid] > target:
+                right = mid - 1
+            elif nums[mid] < target:
+                left = mid + 1
+            else:
+                return mid
+        return -1
+
+
+if __name__ == '__main__':
+    result = Solution().distributeCoins([2, 7, 11, 15], 0)
+    print(result)

999-算法思想/01-二分查找/problem_solving_02.py

+"""
+二分查找改变版
+"""
+
+from typing import List
+
+
+class Solution:
+    def distributeCoins(self, nums: List[int], target: int) -> int:
+        """
+        二分查找改变版,如果增大了右边界,那最后的结果肯定不能取到right
+        :param nums:
+        :param target:
+        :return:
+        """
+        left, right = 0, len(nums)
+        while left < right:
+            mid = (left + right) >> 1
+            if nums[mid] > target:
+                right = mid
+            elif nums[mid] < target:
+                left = mid + 1
+            else:
+                return mid
+        return -1
+
+
+if __name__ == '__main__':
+    result = Solution().distributeCoins([2, 7, 11, 15], 11)
+    print(result)

999-算法思想/01-二分查找/problem_solving_03.py

+"""
+二分查找平衡版
+"""
+
+from typing import List
+
+
+class Solution:
+    def distributeCoins(self, nums: List[int], target: int) -> int:
+        """
+        二分查找平衡版
+        :param nums:
+        :param target:
+        :return:
+        """
+        left, right = 0, len(nums)
+        while 1 < right - left:
+            mid = (left + right) >> 1
+            if nums[mid] > target:
+                right = mid
+            else:
+                left = mid
+        return left if target == nums[left] else -1
+
+
+if __name__ == '__main__':
+    result = Solution().distributeCoins([2, 7, 11, 15], 6)
+    print(result)

999-算法思想/01-二分查找/problem_solving_04.py

+"""
+二分查找java版
+"""
+
+from typing import List
+
+
+class Solution:
+    def distributeCoins(self, nums: List[int], target: int) -> int:
+        """
+        二分查找java版,返回插入位置加1取反,加1的目的是区别0的位置
+        :param nums:
+        :param target:
+        :return:
+        """
+        left, right = 0, len(nums) - 1
+        while left <= right:
+            mid = (left + right) >> 1
+            if nums[mid] > target:
+                right = mid - 1
+            elif nums[mid] < target:
+                left = mid + 1
+            else:
+                return mid
+        return -left - 1
+
+
+if __name__ == '__main__':
+    result = Solution().distributeCoins([2, 7, 11, 15], 1)
+    print(result)

999-算法思想/01-二分查找/problem_solving_05.py

+"""
+二分查找Leftmost
+"""
+
+from typing import List
+
+
+class Solution:
+    def distributeCoins(self, nums: List[int], target: int) -> int:
+        """
+        二分查找Leftmost,最左侧的重复元素
+        :param nums:
+        :param target:
+        :return:
+        """
+        left, right = 0, len(nums) - 1
+        candidate = -1
+        while left <= right:
+            mid = (left + right) >> 1
+            if nums[mid] > target:
+                right = mid - 1
+            elif nums[mid] < target:
+                left = mid + 1
+            else:
+                # 找到后把值给候选人,右指针继续递减
+                candidate = mid
+                right = mid - 1
+        return candidate
+
+
+if __name__ == '__main__':
+    result = Solution().distributeCoins([1, 2, 4, 4, 5, 6, 7], 4)
+    # result = Solution().distributeCoins([1, 2, 4, 4, 4, 5, 6, 7], 4)
+    print(result)

999-算法思想/01-二分查找/problem_solving_06.py

+"""
+二分查找Rightmost
+"""
+
+from typing import List
+
+
+class Solution:
+    def distributeCoins(self, nums: List[int], target: int) -> int:
+        """
+        二分查找Rightmost,最右侧的重复元素
+        :param nums:
+        :param target:
+        :return:
+        """
+        left, right = 0, len(nums) - 1
+        candidate = -1
+        while left <= right:
+            mid = (left + right) >> 1
+            if nums[mid] > target:
+                right = mid - 1
+            elif nums[mid] < target:
+                left = mid + 1
+            else:
+                # 找到后把值给候选人,右指针继续递减
+                candidate = mid
+                left = mid + 1
+        return candidate
+
+
+if __name__ == '__main__':
+    # result = Solution().distributeCoins([1, 2, 4, 4, 5, 6, 7], 4)
+    result = Solution().distributeCoins([1, 2, 4, 4, 4, 5, 6, 7], 4)
+    print(result)

999-算法思想/01-二分查找/problem_solving_07.py

+"""
+二分查找Leftmost
+"""
+
+from typing import List
+
+
+class Solution:
+    def distributeCoins(self, nums: List[int], target: int) -> int:
+        """
+        二分查找Leftmost,小于等于左侧的的位置
+        :param nums:
+        :param target:
+        :return:
+        """
+        left, right = 0, len(nums) - 1
+        while left <= right:
+            mid = (left + right) >> 1
+            if nums[mid] >= target:
+                # 相等了不想返回,继续压缩右指针
+                right = mid - 1
+            else:
+                left = mid + 1
+        return left
+
+
+if __name__ == '__main__':
+    # result = Solution().distributeCoins([1, 2, 4, 4, 5, 6, 7], 4)
+    result = Solution().distributeCoins([1, 2, 4, 4, 4, 5, 6, 7], 3)
+    print(result)

999-算法思想/01-二分查找/problem_solving_08.py

+"""
+二分查找Rightmost
+"""
+
+from typing import List
+
+
+class Solution:
+    def distributeCoins(self, nums: List[int], target: int) -> int:
+        """
+        二分查找Rightmost,大于最右侧的重复元素
+        :param nums:
+        :param target:
+        :return:
+        """
+        left, right = 0, len(nums) - 1
+        while left <= right:
+            mid = (left + right) >> 1
+            if nums[mid] > target:
+                right = mid - 1
+            else:
+                # 最后等于最后一个目标值的时候,又加了一次,所以在结果的时候需要减1
+                left = mid + 1
+        return left - 1
+
+
+if __name__ == '__main__':
+    # result = Solution().distributeCoins([1, 2, 4, 4, 5, 6, 7], 4)
+    result = Solution().distributeCoins([1, 2, 4, 4, 4, 6, 7], 5)
+    print(result)

999-算法思想/01-二分查找/problem_solving_09.py

+"""
+二分查找Rightmost,插入元素在最右边
+"""
+
+from typing import List
+
+
+class Solution:
+    def distributeCoins(self, nums: List[int], target: int) -> int:
+        """
+        二分查找Rightmost,插入元素在最右边,返回的是插入的index,如果是排名需要再加1
+        :param nums:
+        :param target:
+        :return:
+        """
+        left, right = 0, len(nums) - 1
+        while left <= right:
+            mid = (left + right) >> 1
+            if nums[mid] > target:
+                right = mid - 1
+            else:
+                # 最后等于最后一个目标值的时候,又加了一次,所以在结果的时候需要减1
+                left = mid + 1
+        return left
+
+
+if __name__ == '__main__':
+    # result = Solution().distributeCoins([1, 2, 4, 4, 5, 6, 7], 4)
+    result = Solution().distributeCoins([1, 2, 4, 4, 4, 6, 7], 5)
+    print(result)