scratch @ 753ee96db5676dd9ecc5bf980cac917885c01de2

A algos/binary_search.go

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                +package algos

              
                
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                +

              
                
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                +func BinarySearch(arr []int, target int) int {

              
                
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                +	lo, hi := 0, len(arr)-1

              
                
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                +	for lo <= hi {

              
                
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                +		mid := lo + (hi-lo)/2

              
                
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                +		if arr[mid] == target {

              
                
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                +			return mid

              
                
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                +		} else if arr[mid] < target {

              
                
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                +			lo = mid + 1

              
                
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                +		} else {

              
                
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                +			hi = mid - 1

              
                
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                +		}

              
                
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                +	}

              
                
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                +	return -1

              
                
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                +}

              

A algos/binary_search_test.go

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                +package algos

              
                
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                +

              
                
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                +import "testing"

              
                
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                +

              
                
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                +func TestBinarySearch(t *testing.T) {

              
                
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                +	inp := []int{2, 3, 5, 6, 8, 10}

              
                
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                +

              
                
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                +	is(t, BinarySearch(inp, 420), -1)

              
                
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                +	is(t, BinarySearch(inp, 6), 3)

              
                
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                +}