126 lines
2.4 KiB
Go
126 lines
2.4 KiB
Go
package main
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import (
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"fmt"
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"math/rand"
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"strconv"
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"time"
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)
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func main() {
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//list := []int{1, 2, 3, 4, 5, 6, 7}
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//x := RecursiveBinarySearch(list, getVal(), 0, len(list)-1)
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//fmt.Println(x)
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testTimed(10000000)
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}
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func RecursiveBinarySearch(list []int, value int, start int, end int) int {
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var mid int = (start + end) / 2
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if start == (end - 1) {
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if list[mid] == value {
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return mid
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}
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return -1
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}
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if value < list[mid] {
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return RecursiveBinarySearch(list, value, start, mid)
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}
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return RecursiveBinarySearch(list, value, mid, end)
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}
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func getVal() (value int) {
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var input string
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fmt.Println("What value would you like to find in the list:")
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fmt.Scan(&input)
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value, err := strconv.Atoi(input)
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if err != nil {
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fmt.Println("Invalid Input")
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return getVal()
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}
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return
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}
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func generateList(value int) (list []int) {
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for i := 1; i <= value; i++ {
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list = append(list, i)
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}
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return
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}
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func generateRandomList(value int) (list []int) {
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for i := 1; i <= value; i++ {
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list = append(list, rand.Intn(value))
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}
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return
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}
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func testTimed(value int) {
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const mult int = 1000000
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for i := 1; i <= value; i++ {
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start := time.Now()
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list := generateRandomList(i * mult)
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list = mergeSort(list, 0, len(list)-1)
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rnd := rand.Intn(i*mult) + 1
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x := RecursiveBinarySearch(list, rnd, 0, len(list)-1)
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//fmt.Println(time.Now().Sub(start), x, i*1000, "items")
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fmt.Println("found number ", rnd, ":", x, " in a list of ", len(list), " items in ", time.Since(start))
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}
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}
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func mergeSort(nums []int, start int, end int) []int {
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if start == end {
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return []int{nums[start]}
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}
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var mid int = ((end - start) / 2) + start
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//Assign values back into Left and right
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left := mergeSort(nums, start, mid)
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right := mergeSort(nums, mid+1, end)
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var combined []int
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//Pointers for new array
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leftPointer, rightPointer := 0, 0
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for leftPointer <= len(left)-1 || rightPointer <= len(right)-1 {
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if leftPointer == len(left) {
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addValue(&combined, right[rightPointer], &rightPointer)
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} else if rightPointer == len(right) {
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addValue(&combined, left[leftPointer], &leftPointer)
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} else {
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if left[leftPointer] <= right[rightPointer] {
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addValue(&combined, left[leftPointer], &leftPointer)
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} else {
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addValue(&combined, right[rightPointer], &rightPointer)
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}
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}
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}
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return combined
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}
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func addValue(nums *[]int, value int, pointer *int) {
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*nums = append(*nums, value)
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*pointer++
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}
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