题目：Recaman's Sequence (POJ 2081)

链接：

#include 
      

#include 
      

using namespace std;

bool exist[9999999];

int recaman[500001];

int main(int argc, char **argv)

{

int k;

recaman[0] = 0;

memset(exist, 0, sizeof(exist));

for (int i = 1; i <= 500000; ++i)

{

if (recaman[i - 1] - i > 0 && !exist[recaman[i - 1] - i])

{

const int ak = recaman[i - 1] - i;

recaman[i] = ak;

exist[ak] = true;

}

else

{

const int ak = recaman[i - 1] + i;

recaman[i] = ak;

exist[ak] = true;

}

}

while (true)

{

cin >> k;

if (k == -1)

{

break;

}

cout << recaman[k] << endl;

}

return 0;

}