52 lines
1.0 KiB
Go
52 lines
1.0 KiB
Go
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package arrays
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import "fmt"
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/*
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Given a non-empty array of int, every element appears twice except for 1.
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Find that element.
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*/
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/*
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Hash table approach
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Time: O(n)
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Space: O(n)
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*/
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func singleNumberWithHashTable(nums [] int) int{
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counts := make(map[int] int)
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for _, num := range nums{
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counts[num]++
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}
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for key, value := range counts{
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if value == 1{
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return key
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}
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}
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return -1
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}
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/*
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Bit-manipulation approach
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Time: O(n)
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Space: O(1)
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*/
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func singleNumberWithConstantSpace(nums [] int) int{
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result := 0
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for _, num := range nums{
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result ^= num
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}
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return result
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}
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func runSingleNumber(){
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input1 := []int{2,2,1}
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input2 := []int{4,1,2,1,2}
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fmt.Printf("The Single Number for input 1 is %d\n",singleNumberWithConstantSpace(input1))
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fmt.Printf("The Single Number for input 2 is %d\n",singleNumberWithConstantSpace(input2))
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fmt.Printf("The Single Number for input 1 is %d\n",singleNumberWithHashTable(input1))
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fmt.Printf("The Single Number for input 2 is %d\n",singleNumberWithHashTable(input2))
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}
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