题目

Largest Rectangle in Histogram

Given n non-negative integers representing the histogram’s bar height where the width of each bar is 1, find the area of largest rectangle in the histogram.

Above is a histogram where width of each bar is 1, given height = [2,1,5,6,2,3].

The largest rectangle is shown in the shaded area, which has area = 10 unit.

Example:

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> Input: [2,1,5,6,2,3] > Output: 10 >

题目

Maximum Product Subarray

Given an integer array nums, find the contiguous subarray within an array (containing at least one number) which has the largest product.

Example 1:

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> Input: [2,3,-2,4] > Output: 6 > Explanation: [2,3] has the largest product 6. >

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Example 2:

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> Input: [-2,0,-1] > Output: 0 > Explanation: The result cannot be 2, because [-2,-1] is not a subarray. >

题目

Edit Distance

Given two words word1 and word2, find the minimum number of operations required to convert word1 to word2.

You have the following 3 operations permitted on a word:

1. Insert a character
2. Delete a character
3. Replace a character

Example 1:

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> Input: word1 = "horse", word2 = "ros" > Output: 3 > Explanation: > horse -> rorse (replace 'h' with 'r') > rorse -> rose (remove 'r') > rose -> ros (remove 'e') >

>

Example 2:

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> Input: word1 = "intention", word2 = "execution" > Output: 5 > Explanation: > intention -> inention (remove 't') > inention -> enention (replace 'i' with 'e') > enention -> exention (replace 'n' with 'x') > exention -> exection (replace 'n' with 'c') > exection -> execution (insert 'u') >