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Coin Change (M) 题目 You are given coins of different denominations and a total amount of money amount. Write a function to compute the fewest number of 阅读全文
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Reverse String (E) 题目 Write a function that reverses a string. The input string is given as an array of characters char[]. Do not allocate extra space 阅读全文
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Range Sum Query 2D - Immutable (M) 题目 Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (ro 阅读全文
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Range Sum Query - Immutable (E) 题目 Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive. Example: Give 阅读全文
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First Missing Positive (H) 题目 Given an unsorted integer array, find the smallest missing positive integer. Example 1: Input: [1,2,0] Output: 3 Example 阅读全文
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Combination Sum II (M) 题目 Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidate 阅读全文
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Combination Sum (M) 题目 Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combinations i 阅读全文
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Count and Say (E) 题目 The count-and-say sequence is the sequence of integers with the first five terms as following: 1. 1 2. 11 3. 21 4. 1211 5. 111221 阅读全文