ACM模版
约瑟夫环问题
int main(int argc, const char * argv[])
{
int n, k, m;
while (cin >> n >> k >> m, n || k || m)
{
int i, d, s = 0;
for (i = 2; i <= n; i++)
{
s = (s + k) % i;
}
k = k % n;
if (k == 0)
{
k = n;
}
d = (s + 1) + (m - k);
if (d >= 1 && d <= n)
{
cout << d << '\n';
}
else if (d < 1)
{
cout << n + d << '\n';
}
else if (d > n)
{
cout << d % n << '\n';
}
}
return 0;
}
函数图像法
unsigned long long n, k;
int main()
{
cin >> n >> k;
long long y = k % 2;
long long x = 2, t = 0;
long long z1 = y, z2 = x;
while (x <= n)
{
z1 = y;
z2 = x;
t = (x - y) / (k - 1);
if (t == 0)
{
t++;
}
y = y + t * k - ((y + t * k) / (x + t)) * (x + t);
x += t;
}
cout << (z1 + (n - z2) * k) % n + 1 << endl;
return 0;
}