DSA/Arrays/Search.java at main · nitin-kumar-code/DSA · GitHub

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/*
LeetCode: 34. Find First and Last Position of Element in Sorted Array

Difficulty: Medium

Pattern: Arrays and Binary Search

class Solution {
    public int[] searchRange(int[] nums, int target) {
        int[] ans = {-1, -1};

        ans[0] = search(nums, target, true);

        if (ans[0] != -1) {
            ans[1] = search(nums, target, false);
        }

        return ans;
    }

    int search(int[] nums, int target, boolean findStartIndex) {
        int ans = -1;
        int start = 0;
        int end = nums.length - 1;

        while (start <= end) {
            int mid = start + (end - start) / 2;

            if (target < nums[mid]) {
                end = mid - 1;
            } else if (target > nums[mid]) {
                start = mid + 1;
            } else {
                ans = mid;

                if (findStartIndex) {
                    end = mid - 1;
                } else {
                    start = mid + 1;
                }
            }
        }

        return ans;
    }
}
*/

/*
LeetCode: 33. Search in Rotated Sorted Array

Difficulty: Medium

Topic: Arrays and Binary Search

class Solution {
    public int search(int[] nums, int target) {
        int low = 0;
        int high = nums.length - 1;

        while (low <= high) {
            int mid = low + (high - low) / 2;

            if (nums[mid] == target) {
                return mid;
            }

            // Left half is sorted
            if (nums[low] <= nums[mid]) {
                if (nums[low] <= target && target < nums[mid]) {
                    high = mid - 1;
                } else {
                    low = mid + 1;
                }
            }
            // Right half is sorted
            else {
                if (nums[mid] < target && target <= nums[high]) {
                    low = mid + 1;
                } else {
                    high = mid - 1;
                }
            }
        }

        return -1;
    }
}
*/

/*
LeetCode: 540. Single Element in a Sorted Array

Difficulty: Medium

Topic: Arrays and Binary Search

class Solution {
    public int singleNonDuplicate(int[] nums) {

        int start = 0;
        int end = nums.length - 1;

        while (start < end) {

            int mid = start + (end - start) / 2;

            if (mid % 2 == 1) {
                mid--;
            }

            if (nums[mid] == nums[mid + 1]) {
                start = mid + 2;
            } else {
                end = mid;
            }
        }

        return nums[start];
    }
}
*/

/*
LeetCode: 875. Koko Eating Bananas

Difficulty: Medium

Topic: Arrays and Binary Search

class Solution {

    public int minEatingSpeed(int[] piles, int h) {

        int low = 1;
        int high = 0;

        // Find the maximum pile
        for (int pile : piles) {
            high = Math.max(high, pile);
        }

        int answer = high;

        while (low <= high) {

            int mid = low + (high - low) / 2;

            long hours = 0;

            // Calculate hours needed at speed = mid
            for (int pile : piles) {

                hours += (pile + mid - 1) / mid;
            }

            if (hours <= h) {

                answer = mid;
                high = mid - 1;

            } else {

                low = mid + 1;
            }
        }

        return answer;
    }
}

*/