43 lines
1.4 KiB
Kotlin
43 lines
1.4 KiB
Kotlin
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// （版本二）左闭右闭区间
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class Solution {
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fun search(nums: IntArray, target: Int): Int {
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var left = 0
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var right = nums.size - 1 // [left,right] 右侧为闭区间，right 设置为 nums.size - 1
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while (left <= right) {
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val mid = (left + right) / 2
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if (nums[mid] < target) left = mid + 1
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else if (nums[mid] > target) right = mid - 1 // 代码的核心，循环中 right 是闭区间，这里也应是闭区间
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else return mid
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}
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return -1 // 没有找到 target ，返回 -1
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}
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}
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class Solution_2 {
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fun search(nums: IntArray, target: Int): Int {
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var left = 0
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var right = nums.size // [left,right) 右侧为开区间，
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while (left < right) {
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val mid = (left + right) / 2
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if (nums[mid] < target) left = mid + 1
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else if (nums[mid] > target) right = mid // 代码的核心，循环中 right 是开区间，这里应是开区间
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else return mid
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}
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return -1 // 没有找到 target ，返回 -1
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}
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}
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// 测试用例
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fun main() {
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val nums = intArrayOf( 0, 1, 2, 4, 5, 6, 7)
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val target = 0
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val solution = Solution()
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val result = solution.search(nums, target)
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val solution2 = Solution_2()
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val result2 = solution2.search(nums, target)
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println("Solution 1: $result") // 0
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println("Solution 2: $result2") // 0
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}
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