20 lines
388 B
C++
20 lines
388 B
C++
#include <iostream>
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class Solution {
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public:
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// O(log(n))
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static int lastRemaining(int n) {
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// int cnt = 0, ret = 1;
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int ret = 1, cnt = __builtin_clz(n) ^ 31;
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// for (int i = n; i >>= 1; ++cnt);
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for (int i = 0; i < cnt; ++i, n >>= 1)
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ret += !(1 & i) || (1 & n) ? (1 << i) : 0;
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return ret;
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}
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};
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int main() {
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std::printf("%d\n", Solution::lastRemaining(1));
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return 0;
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}
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