38 lines
819 B
JavaScript
38 lines
819 B
JavaScript
/*
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* @lc app=leetcode id=34 lang=javascript
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*
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* [34] Find First and Last Position of Element in Sorted Array
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*/
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/**
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* @param {number[]} nums
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* @param {number} target
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* @return {number[]}
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*/
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var searchRange = function(nums, target) {
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// 题目要求时间复杂度为O(logn)因此很自然想到二分法
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let start = 0;
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let end = nums.length - 1;
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while (start <= end) {
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const mid = start + ((end - start) >> 1);
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if (nums[mid] === target) {
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let left = 0;
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let right = 0;
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while (nums[mid - left] === target) {
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left++;
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}
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while (nums[mid + right] === target) {
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right++;
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}
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return [mid - left + 1, mid + right - 1];
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} else if (nums[mid] > target) {
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end = mid - 1;
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} else {
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start = mid + 1;
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}
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}
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return [-1, -1];
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};
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