Given an array of integers nums, calculate the pivot index of this array.
The pivot index is the index where the sum of all the numbers strictly to the left of the index is equal to the sum of all the numbers strictly to the index's right.
\n\nIf the index is on the left edge of the array, then the left sum is 0 because there are no elements to the left. This also applies to the right edge of the array.
Return the leftmost pivot index. If no such index exists, return -1.
\n\n\n
Example 1:
\n\n\nInput: nums = [1,7,3,6,5,6]\nOutput: 3\nExplanation:\nThe pivot index is 3.\nLeft sum = nums[0] + nums[1] + nums[2] = 1 + 7 + 3 = 11\nRight sum = nums[4] + nums[5] = 5 + 6 = 11\n\n\n
Example 2:
\n\n\nInput: nums = [1,2,3]\nOutput: -1\nExplanation:\nThere is no index that satisfies the conditions in the problem statement.\n\n
Example 3:
\n\n\nInput: nums = [2,1,-1]\nOutput: 0\nExplanation:\nThe pivot index is 0.\nLeft sum = 0 (no elements to the left of index 0)\nRight sum = nums[1] + nums[2] = 1 + -1 = 0\n\n\n
\n
Constraints:
\n\n1 <= nums.length <= 104-1000 <= nums[i] <= 1000\n
Note: This question is the same as 1991: https://leetcode.com/problems/find-the-middle-index-in-array/
\n", "translatedTitle": null, "translatedContent": null, "isPaidOnly": false, "difficulty": "Easy", "likes": 3093, "dislikes": 367, "isLiked": null, "similarQuestions": "[{\"title\": \"Subarray Sum Equals K\", \"titleSlug\": \"subarray-sum-equals-k\", \"difficulty\": \"Medium\", \"translatedTitle\": null}, {\"title\": \"Find the Middle Index in Array\", \"titleSlug\": \"find-the-middle-index-in-array\", \"difficulty\": \"Easy\", \"translatedTitle\": null}, {\"title\": \"Maximum Sum Score of Array\", \"titleSlug\": \"maximum-sum-score-of-array\", \"difficulty\": \"Medium\", \"translatedTitle\": null}]", "exampleTestcases": "[1,7,3,6,5,6]\n[1,2,3]\n[2,1,-1]", "categoryTitle": "Algorithms", "contributors": [], "topicTags": [ { "name": "Array", "slug": "array", "translatedName": null, "__typename": "TopicTagNode" }, { "name": "Prefix Sum", "slug": "prefix-sum", "translatedName": null, "__typename": "TopicTagNode" } ], "companyTagStats": null, "codeSnippets": [ { "lang": "C++", "langSlug": "cpp", "code": "class Solution {\npublic:\n int pivotIndex(vectorCompiled with clang 11 using the latest C++ 17 standard.
Your code is compiled with level two optimization (-O2). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.
Most standard library headers are already included automatically for your convenience.
\"], \"java\": [\"Java\", \" OpenJDK 17 . Java 8 features such as lambda expressions and stream API can be used.
Most standard library headers are already included automatically for your convenience.
\\r\\nIncludes Pair class from https://docs.oracle.com/javase/8/javafx/api/javafx/util/Pair.html.
Python 2.7.12.
Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.
\\r\\n\\r\\nFor Map/TreeMap data structure, you may use sortedcontainers library.
\\r\\n\\r\\nNote that Python 2.7 will not be maintained past 2020. For the latest Python, please choose Python3 instead.
\"], \"c\": [\"C\", \"Compiled with gcc 8.2 using the gnu99 standard.
Your code is compiled with level one optimization (-O1). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.
Most standard library headers are already included automatically for your convenience.
\\r\\n\\r\\nFor hash table operations, you may use uthash. \\\"uthash.h\\\" is included by default. Below are some examples:
\\r\\n\\r\\n1. Adding an item to a hash.\\r\\n
\\r\\nstruct hash_entry {\\r\\n int id; /* we'll use this field as the key */\\r\\n char name[10];\\r\\n UT_hash_handle hh; /* makes this structure hashable */\\r\\n};\\r\\n\\r\\nstruct hash_entry *users = NULL;\\r\\n\\r\\nvoid add_user(struct hash_entry *s) {\\r\\n HASH_ADD_INT(users, id, s);\\r\\n}\\r\\n\\r\\n\\r\\n\\r\\n2. Looking up an item in a hash:\\r\\n
\\r\\nstruct hash_entry *find_user(int user_id) {\\r\\n struct hash_entry *s;\\r\\n HASH_FIND_INT(users, &user_id, s);\\r\\n return s;\\r\\n}\\r\\n\\r\\n\\r\\n\\r\\n3. Deleting an item in a hash:\\r\\n
\\r\\nvoid delete_user(struct hash_entry *user) {\\r\\n HASH_DEL(users, user); \\r\\n}\\r\\n\\r\\n\"], \"csharp\": [\"C#\", \"\\r\\n\\r\\nYour code is compiled with debug flag enabled (/debug).
Node.js 16.13.2.
Your code is run with --harmony flag, enabling new ES6 features.
lodash.js library is included by default.
\\r\\n\\r\\nFor Priority Queue / Queue data structures, you may use datastructures-js/priority-queue and datastructures-js/queue.
\"], \"ruby\": [\"Ruby\", \"Ruby 3.1
Some common data structure implementations are provided in the Algorithms module: https://www.rubydoc.info/github/kanwei/algorithms/Algorithms
\"], \"swift\": [\"Swift\", \"Swift 5.5.2.
Go 1.17.6.
Support https://godoc.org/github.com/emirpasic/gods library.
\"], \"python3\": [\"Python3\", \"Python 3.10.
Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.
\\r\\n\\r\\nFor Map/TreeMap data structure, you may use sortedcontainers library.
\"], \"scala\": [\"Scala\", \"Scala 2.13.7.
Kotlin 1.3.10.
Rust 1.58.1
Supports rand v0.6\\u00a0from crates.io
\"], \"php\": [\"PHP\", \"PHP 8.1.
With bcmath module
\"], \"typescript\": [\"Typescript\", \"TypeScript 4.5.4, Node.js 16.13.2.
Your code is run with --harmony flag, enabling new ES2020 features.
lodash.js library is included by default.
\"], \"racket\": [\"Racket\", \"Run with Racket 8.3.