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Commit 7462b51

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solves find first and last position of element in sorted array
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‎README.md

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| 29 | [Divide Two Integers](https://leetcode.com/problems/divide-two-integers) | [![Java](assets/java.png)](src/DivideTwoIntegers.java) | |
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| 31 | [Next Permutation](https://leetcode.com/problems/next-permutation) | [![Java](assets/java.png)](src/NextPermutation.java) | |
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| 33 | [Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array) | [![Java](assets/java.png)](src/SearchInRotatedSortedArray.java) | |
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| 33 | [Find First and Last Position of Element in Sorted Array](https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array) | [![Java](assets/java.png)](src/FindFirstAndLastPositionOfElementInSortedArray.java) | |
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| 35 | [Search Inserted Position](https://leetcode.com/problems/search-insert-position/) | [![Java](assets/java.png)](src/SearchInsertPosition.java) [![Python](assets/python.png)](python/search_insert_position.py) | |
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| 38 | [Count and Say](https://leetcode.com/problems/count-and-say) | [![Java](assets/java.png)](src/CountAndSay.java) [![Python](assets/python.png)](python/count_and_say.py) | |
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| 53 | [Maximum SubArray](https://leetcode.com/problems/maximum-subarray) | [![Java](assets/java.png)](src/MaximumSubArray.java) [![Python](assets/python.png)](python/maximum_sum_subarray.py) | |
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// https://leetcode.com/problems/find-first-and-last-position-of-element-in-sorted-array
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// T: O(logN)
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// S: O(1)
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public class FindFirstAndLastPositionOfElementInSortedArray {
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public int[] searchRange(int[] nums, int target) {
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return new int[] {
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leftMostIndex(nums, target),
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rightMostIndex(nums, target)
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};
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}
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private int leftMostIndex(int[] array, int target) {
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int left = 0, right = array.length - 1, middle;
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while (left <= right) {
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middle = left + (right - left) / 2;
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if (array[middle] == target) {
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if (middle - 1 >= 0 && array[middle - 1] == target) right = middle - 1;
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else return middle;
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} else if (array[middle] > target) right = middle - 1;
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else left = middle + 1;
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}
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return -1;
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}
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private int rightMostIndex(int[] array, int target) {
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int left = 0, right = array.length - 1, middle;
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while (left <= right) {
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middle = left + (right - left) / 2;
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if (array[middle] == target) {
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if (middle + 1 < array.length && array[middle + 1] == target) left = middle + 1;
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else return middle;
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} else if (array[middle] > target) right = middle - 1;
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else left = middle + 1;
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}
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return -1;
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}
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}

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