34 lines
688 B
Swift
34 lines
688 B
Swift
var dp: [Int64] = Array(repeating: 0, count: 55)
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for n in 1...54 {
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dp[n] = 2*dp[n-1] + (1 << (n-1))
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}
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func countOne(_ N: Int64) -> Int64 {
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var res: Int64 = 0
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var n: Int64 = N
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for i in stride(from: 54, to: 0, by: -1) {
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let LSB: Int64 = (1 << (i-1)) & n
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if LSB != 0{
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res += dp[i-1]
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res += n - (1 << (i-1)) + 1
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}
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n &= ((1 << (i-1)) - 1)
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}
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return res
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}
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func main() {
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guard let input = readLine() else { return }
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let nums: [Int64] = input.split(separator: " ").compactMap{Int64($0)}
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let ans: Int64 = countOne(nums[1]) - countOne(nums[0]-1)
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print(ans)
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}
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main()
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