65 lines
2.2 KiB
Kotlin
65 lines
2.2 KiB
Kotlin
/**
|
|
* File: binary_search_insertion.kt
|
|
* Created Time: 2024-01-25
|
|
* Author: curtishd (1023632660@qq.com)
|
|
*/
|
|
|
|
package chapter_searching
|
|
|
|
/* Binary search for insertion point (no duplicate elements) */
|
|
fun binarySearchInsertionSimple(nums: IntArray, target: Int): Int {
|
|
var i = 0
|
|
var j = nums.size - 1 // Initialize double closed interval [0, n-1]
|
|
while (i <= j) {
|
|
val m = i + (j - i) / 2 // Calculate midpoint index m
|
|
if (nums[m] < target) {
|
|
i = m + 1 // Target is in interval [m+1, j]
|
|
} else if (nums[m] > target) {
|
|
j = m - 1 // Target is in interval [i, m-1]
|
|
} else {
|
|
return m // Found target, return insertion point m
|
|
}
|
|
}
|
|
// Did not find target, return insertion point i
|
|
return i
|
|
}
|
|
|
|
/* Binary search for insertion point (with duplicate elements) */
|
|
fun binarySearchInsertion(nums: IntArray, target: Int): Int {
|
|
var i = 0
|
|
var j = nums.size - 1 // Initialize double closed interval [0, n-1]
|
|
while (i <= j) {
|
|
val m = i + (j - i) / 2 // Calculate midpoint index m
|
|
if (nums[m] < target) {
|
|
i = m + 1 // Target is in interval [m+1, j]
|
|
} else if (nums[m] > target) {
|
|
j = m - 1 // Target is in interval [i, m-1]
|
|
} else {
|
|
j = m - 1 // First element less than target is in interval [i, m-1]
|
|
}
|
|
}
|
|
// Return insertion point i
|
|
return i
|
|
}
|
|
|
|
/* Driver Code */
|
|
fun main() {
|
|
// Array without duplicate elements
|
|
var nums = intArrayOf(1, 3, 6, 8, 12, 15, 23, 26, 31, 35)
|
|
println("\nArray nums = ${nums.contentToString()}")
|
|
// Binary search for insertion point
|
|
for (target in intArrayOf(6, 9)) {
|
|
val index = binarySearchInsertionSimple(nums, target)
|
|
println("Index of the insertion point for element $target = $index")
|
|
}
|
|
|
|
// Array with duplicate elements
|
|
nums = intArrayOf(1, 3, 6, 6, 6, 6, 6, 10, 12, 15)
|
|
println("\nArray nums = ${nums.contentToString()}")
|
|
|
|
// Binary search for insertion point
|
|
for (target in intArrayOf(2, 6, 20)) {
|
|
val index = binarySearchInsertion(nums, target)
|
|
println("Index of the insertion point for element $target = $index")
|
|
}
|
|
} |