{ "data": { "question": { "questionId": "2448", "questionFrontendId": "2364", "boundTopicId": null, "title": "Count Number of Bad Pairs", "titleSlug": "count-number-of-bad-pairs", "content": "

You are given a 0-indexed integer array nums. A pair of indices (i, j) is a bad pair if i < j and j - i != nums[j] - nums[i].

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Return the total number of bad pairs in nums.

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Example 1:

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\nInput: nums = [4,1,3,3]\nOutput: 5\nExplanation: The pair (0, 1) is a bad pair since 1 - 0 != 1 - 4.\nThe pair (0, 2) is a bad pair since 2 - 0 != 3 - 4, 2 != -1.\nThe pair (0, 3) is a bad pair since 3 - 0 != 3 - 4, 3 != -1.\nThe pair (1, 2) is a bad pair since 2 - 1 != 3 - 1, 1 != 2.\nThe pair (2, 3) is a bad pair since 3 - 2 != 3 - 3, 1 != 0.\nThere are a total of 5 bad pairs, so we return 5.\n
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Example 2:

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\nInput: nums = [1,2,3,4,5]\nOutput: 0\nExplanation: There are no bad pairs.\n
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Constraints:

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i != nums[j] - nums[i]) is the same as (nums[i] - i != nums[j] - j).", "Keep a counter of nums[i] - i. 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Compiled with clang 11 using the latest C++ 20 standard.

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Most standard library headers are already included automatically for your convenience.

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OpenJDK 17. Java 8 features such as lambda expressions and stream API can be used.

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Most standard library headers are already included automatically for your convenience.

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Python 2.7.12.

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Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.

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For Map/TreeMap data structure, you may use sortedcontainers library.

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C# 10 with .NET 6 runtime

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Some common data structure implementations are provided in the Algorithms module: https://www.rubydoc.info/github/kanwei/algorithms/Algorithms

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Python 3.10.

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TypeScript 5.1.6, Node.js 16.13.2.

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Dart 2.17.3

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