[LC] 0081 Search in Rotated Sorted Array II

Java

/**
 * <a href="https://leetcode.cn/problems/search-in-rotated-sorted-array-ii/">Search in Rotated Sorted Array II</a>
 * 数组；二分查找
 */
class Solution {
    public boolean search(int[] nums, int target) {
        int n = nums.length;
        if (n == 0) {
            return false;
        }
        if (n == 1) {
            return nums[0] == target;
        }

        int l = 0, r = n - 1;
        while (l <= r) {
            int mid = l + (r - l) / 2;
            if (nums[mid] == target) {
                return true;
            }

            if (nums[l] == nums[mid] && nums[mid] == nums[r]) {
                l++;
                r--;
            } else if (nums[l] <= nums[mid]) {
                if (nums[l] <= target && target < nums[mid]) {
                    r = mid - 1;
                } else {
                    l = mid + 1;
                }
            } else {
                if (nums[mid] < target && target <= nums[r]) {
                    l = mid + 1;
                } else {
                    r = mid - 1;
                }
            }
        }

        return false;
    }
}

Go

func search(nums []int, target int) bool {
    n := len(nums)
    if n == 0 {
        return false
    }
    if n == 1 {
        return nums[0] == target
    }

    l, r := 0, n-1
    for l <= r {
        mid := (l + r) / 2
        if nums[mid] == target {
            return true
        }

        if nums[l] == nums[mid] && nums[mid] == nums[r] {
            l++
            r--
        } else if nums[l] <= nums[mid] {
            if nums[l] <= target && target < nums[mid] {
                r = mid - 1
            } else {
                l = mid + 1
            }
        } else {
            if nums[mid] < target && target <= nums[r] {
                l = mid + 1
            } else {
                r = mid - 1
            }
        }
    }

    return false
}

JavaScript

/**
 * @param {number[]} nums
 * @param {number} target
 * @return {boolean}
 */
var search = function (nums, target) {
    let n = nums.length;
    if (n === 0) {
        return false;
    }
    if (n === 1) {
        return nums[0] === target;
    }

    let l = 0, r = n - 1;
    while (l <= r) {
        let mid = Math.floor((l + r) / 2);
        if (nums[mid] === target) {
            return true;
        }

        if (nums[l] === nums[mid] && nums[mid] === nums[r]) {
            l++;
            r--;
        } else if (nums[l] <= nums[mid]) {
            if (nums[l] <= target && target < nums[mid]) {
                r = mid - 1;
            } else {
                l = mid + 1;
            }
        } else {
            if (nums[mid] < target && target <= nums[r]) {
                l = mid + 1;
            } else {
                r = mid - 1;
            }
        }
    }

    return false;
};

PHP

class Solution {

    /**
     * @param Integer[] $nums
     * @param Integer $target
     * @return Boolean
     */
    function search(array $nums, int $target): bool {
        $n = count($nums);
        if ($n == 0) {
            return false;
        }
        if ($n == 1) {
            return $nums[0] == $target;
        }

        $l = 0;
        $r = $n - 1;
        while ($l <= $r) {
            $mid = floor(($l + $r) / 2);
            if ($nums[$mid] == $target) {
                return true;
            }

            if ($nums[$l] == $nums[$mid] && $nums[$mid] == $nums[$r]) {
                $l++;
                $r--;
            } else if ($nums[$l] <= $nums[$mid]) {
                if ($nums[$l] <= $target && $target < $nums[$mid]) {
                    $r = $mid - 1;
                } else {
                    $l = $mid + 1;
                }
            } else {
                if ($nums[$mid] < $target && $target <= $nums[$r]) {
                    $l = $mid + 1;
                } else {
                    $r = $mid - 1;
                }
            }
        }

        return false;
    }
}