二次联通门 : BZOJ 1876: [SDOI2009]SuperGCD
/* BZOJ 1876: [SDOI2009]SuperGCD 更相减损术 + 高精 */ #include <cstdio> #include <iostream> #include <vector> #include <iomanip> #include <cassert> #include <algorithm> #include <cstring> const int Big_B = 1000000000; const int Big_L = 9; inline int intcmp_ (int a, int b) { if (a > b) return 1; return a < b ? -1 : 0; } struct Int { #define rg register inline int max (int a, int b) { return a > b ? a : b; } inline int min (int a, int b) { return a < b ? a : b; } std :: vector <int> c; Int () {} typedef long long LL; Int (int x) { for (; x > 0; c.push_back (x % Big_B), x /= Big_B); } Int (LL x) { for (; x > 0; c.push_back (x % Big_B), x /= Big_B); } inline void CrZ () { for (; !c.empty () && c.back () == 0; c.pop_back ()); } inline Int &operator -= (const Int &rhs) { c.resize (max (c.size (), rhs.c.size ())); rg int i, t = 0, S; for (i = 0, S = rhs.c.size (); i < S; ++ i) c[i] -= rhs.c[i] + t, t = c[i] < 0, c[i] += Big_B & (-t); for (i = rhs.c.size (), S = c.size (); t && i < S; ++ i) c[i] -= t, t = c[i] < 0, c[i] += Big_B & (-t); CrZ (); return *this; } inline int Comp (const Int &rhs) const { if (c.size () != rhs.c.size ()) return intcmp_ (c.size (), rhs.c.size ()); for (rg int i = c.size () - 1; i >= 0; -- i) if (c[i] != rhs.c[i]) return intcmp_ (c[i], rhs.c[i]); return 0; } friend inline Int operator - (const Int &lhs, const Int &rhs) { Int res = lhs; return res -= rhs; } friend inline std :: ostream &operator << (std :: ostream &out, const Int &rhs) { if (rhs.c.size () == 0) out << "0"; else { out << rhs.c.back (); for (rg int i = rhs.c.size () - 2; i >= 0; -- i) out << std :: setfill ('0') << std :: setw (Big_L) << rhs.c[i]; } return out; } friend inline std :: istream &operator >> (std :: istream &in, Int &rhs) { static char s[10000]; in >> s + 1; int Len = strlen (s + 1); int v = 0; LL r = 0, p = 1; for (rg int i = Len; i >= 1; -- i) { ++ v; r = r + (s[i] - '0') * p, p *= 10; if (v == Big_L) rhs.c.push_back (r), r = 0, v = 0, p = 1; } if (v != 0) rhs.c.push_back (r); return in; } friend inline bool operator < (const Int &lhs, const Int &rhs) { return lhs.Comp (rhs) < 0; } friend inline bool operator > (const Int &lhs, const Int &rhs) { return lhs.Comp (rhs) > 0; } friend inline bool operator == (const Int &lhs, const Int &rhs) { return lhs.Comp (rhs) == 0; } friend inline bool operator != (const Int &lhs, const Int &rhs) { return lhs.Comp (rhs) != 0; } #undef rg }; int Main () { Int a, b; std :: cin >> a >> b; for (; a != 0 || b != 0; ) { if (a == 0) { std :: cout << b; return 0; } else if (b == 0) { std :: cout << a; return 0;} if (a < b) b -= a; else a -= b; } return 0; } int ZlycerQan = Main (); int main (int argc, char *argv[]) {;}