@[wyhnet](/user/527425) 你`string`用`scanf`？
by Ruiqun2009 @ 2022-07-20 14:59:23
@[Ruiqun2009](/user/589895) 感谢指教（小声bb:ios::sync_with_stdio(0)挺快的）
by wyhnet @ 2022-07-20 15:03:31
@[wyhnet](/user/527425) 带火车头的快读，能不比`cin`快吗？
```cpp
#define GCC optimize("Ofast")
#define GCC optimize("inline")
#define GCC optimize("-fgcse")
#define GCC optimize("-fgcse-lm")
#define GCC optimize("-fipa-sra")
#define GCC optimize("-ftree-pre")
#define GCC optimize("-ftree-vrp")
#define GCC optimize("-fpeephole2")
#define GCC optimize("-ffast-math")
#define GCC optimize("-fsched-spec")
#define GCC optimize("unroll-loops")
#define GCC optimize("-falign-jumps")
#define GCC optimize("-falign-loops")
#define GCC optimize("-falign-labels")
#define GCC optimize("-fdevirtualize")
#define GCC optimize("-fcaller-saves")
#define GCC optimize("-fcrossjumping")
#define GCC optimize("-fthread-jumps")
#define GCC optimize("-funroll-loops")
#define GCC optimize("-fwhole-program")
#define GCC optimize("-freorder-blocks")
#define GCC optimize("-fschedule-insns")
#define GCC optimize("inline-functions")
#define GCC optimize("-ftree-tail-merge")
#define GCC optimize("-fschedule-insns2")
#define GCC optimize("-fstrict-aliasing")
#define GCC optimize("-fstrict-overflow")
#define GCC optimize("-falign-functions")
#define GCC optimize("-fcse-skip-blocks")
#define GCC optimize("-fcse-follow-jumps")
#define GCC optimize("-fsched-interblock")
#define GCC optimize("-fpartial-inlining")
#define GCC optimize("no-stack-protector")
#define GCC optimize("-freorder-functions")
#define GCC optimize("-findirect-inlining")
#define GCC optimize("-frerun-cse-after-loop")
#define GCC optimize("inline-small-functions")
#define GCC optimize("-finline-small-functions")
#define GCC optimize("-ftree-switch-conversion")
#define GCC optimize("-foptimize-sibling-calls")
#define GCC optimize("-fexpensive-optimizations")
#define GCC optimize("-funsafe-loop-optimizations")
#define GCC optimize("-fdelete-null-pointer-checks")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2")
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <climits>
#include <cmath>
#include <functional>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string.h>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#define inline inline __attribute__((always_inline))
namespace OY {
#define cin OY::inputHelper<1024, 20>::getInstance()
#define getchar() ({char c=cin.getChar_Checked();cin.next();c;})
#define cout OY::outputHelper<1048576>::getInstance()
#define putchar cout.putChar
#define endl '\n'
#define putlog(...) OY::printLog(", ", __VA_ARGS__)
template <uint64_t _BufferSize = 1024, uint64_t _BlockSize = 20>
class inputHelper {
FILE *m_filePtr;
char m_buf[_BufferSize], *m_end, *m_cursor;
bool m_ok;
void flush() {
uint64_t a = m_end - m_cursor;
if (a >= _BlockSize) return;
memmove(m_buf, m_cursor, a);
uint64_t b = fread(m_buf + a, 1, _BufferSize - a, m_filePtr);
m_cursor = m_buf;
if (a + b < _BufferSize) {
m_end = m_buf + a + b;
*m_end = EOF;
}
}
public:
explicit inputHelper(const char *inputFileName) : m_ok(true) {
if (!*inputFileName)
m_filePtr = stdin;
else
m_filePtr = fopen(inputFileName, "rt");
m_end = m_cursor = m_buf + _BufferSize;
}
~inputHelper() { fclose(m_filePtr); }
static inputHelper<_BufferSize, _BlockSize> &getInstance() {
#ifdef OY_LOCAL
static inputHelper<_BufferSize, _BlockSize> s_obj("in.txt");
#else
static inputHelper<_BufferSize, _BlockSize> s_obj("");
#endif
return s_obj;
}
static constexpr bool isBlank(char c) { return c == ' ' || c == '\t' || c == '\n' || c == '\r'; }
static constexpr bool isEndline(char c) { return c == '\n' || c == EOF; }
const char &getChar_Checked() {
if (m_cursor < m_end) return *m_cursor;
uint64_t b = fread(m_buf, 1, _BufferSize, m_filePtr);
m_cursor = m_buf;
if (b < _BufferSize) {
m_end = m_buf + b;
*m_end = EOF;
}
return *m_cursor;
}
const char &getChar_Unchecked() const { return *m_cursor; }
void next() { ++m_cursor; }
void setState(bool _ok) { m_ok = _ok; }
template <typename _Tp, std::enable_if_t<std::is_signed_v<_Tp> & std::is_integral_v<_Tp>> * = nullptr>
inputHelper<_BufferSize, _BlockSize> &operator>>(_Tp &ret) {
while (isBlank(getChar_Checked())) next();
flush();
if (getChar_Unchecked() == '-') {
next();
if (isdigit(getChar_Unchecked())) {
ret = -(getChar_Unchecked() - '0');
while (next(), isdigit(getChar_Unchecked())) ret = ret * 10 - (getChar_Unchecked() - '0');
} else
m_ok = false;
} else {
if (isdigit(getChar_Unchecked())) {
ret = getChar_Unchecked() - '0';
while (next(), isdigit(getChar_Unchecked())) ret = ret * 10 + (getChar_Unchecked() - '0');
} else
m_ok = false;
}
return *this;
}
template <typename _Tp, std::enable_if_t<std::is_unsigned_v<_Tp> & std::is_integral_v<_Tp>> * = nullptr>
inputHelper<_BufferSize, _BlockSize> &operator>>(_Tp &ret) {
while (isBlank(getChar_Checked())) next();
flush();
if (isdigit(getChar_Unchecked())) {
ret = getChar_Unchecked() - '0';
while (next(), isdigit(getChar_Unchecked())) ret = ret * 10 + (getChar_Unchecked() - '0');
} else
m_ok = false;
return *this;
}
template <typename _Tp, std::enable_if_t<std::is_floating_point_v<_Tp>> * = nullptr>
inputHelper<_BufferSize, _BlockSize> &operator>>(_Tp &ret) {
bool neg = false, integer = false, decimal = false;
while (isBlank(getChar_Checked())) next();
flush();
if (getChar_Unchecked() == '-') {
neg = true;
next();
}
if (!isdigit(getChar_Unchecked()) && getChar_Unchecked() != '.') {
m_ok = false;
return *this;
}
if (isdigit(getChar_Unchecked())) {
integer = true;
ret = getChar_Unchecked() - '0';
while (next(), isdigit(getChar_Unchecked())) ret = ret * 10 + (getChar_Unchecked() - '0');
}
if (getChar_Unchecked() == '.') {
next();
if (isdigit(getChar_Unchecked())) {
if (!integer) ret = 0;
decimal = true;
_Tp unit = 0.1;
ret += unit * (getChar_Unchecked() - '0');
while (next(), isdigit(getChar_Unchecked())) {
unit *= 0.1;
ret += unit * (getChar_Unchecked() - '0');
}
}
}
if (!integer && !decimal)
m_ok = false;
else if (neg)
ret = -ret;
return *this;
}
inputHelper<_BufferSize, _BlockSize> &operator>>(char &ret) {
while (isBlank(getChar_Checked())) next();
ret = getChar_Checked();
next();
return *this;
}
inputHelper<_BufferSize, _BlockSize> &operator>>(std::string &ret) {
while (isBlank(getChar_Checked())) next();
if (getChar_Checked() != EOF) {
ret.clear();
do {
ret += getChar_Checked();
next();
} while (!isBlank(getChar_Checked()) && getChar_Unchecked() != EOF);
} else
m_ok = false;
return *this;
}
explicit operator bool() { return m_ok; }
};
template <uint64_t _BufferSize = 1048576>
class outputHelper {
FILE *m_filePtr = nullptr;
char m_buf[_BufferSize], *m_end, *m_cursor;
char m_tempBuf[50], *m_tempBufCursor, *m_tempBufDot;
uint64_t m_floatReserve, m_floatRatio;
public:
outputHelper(const char *outputFileName, int prec = 6) : m_end(m_buf + _BufferSize) {
if (!*outputFileName)
m_filePtr = stdout;
else
m_filePtr = fopen(outputFileName, "wt");
m_cursor = m_buf;
m_tempBufCursor = m_tempBuf;
precision(prec);
}
static outputHelper<_BufferSize> &getInstance() {
#ifdef OY_LOCAL
static outputHelper<_BufferSize> s_obj("out.txt");
#else
static outputHelper<_BufferSize> s_obj("");
#endif
return s_obj;
}
~outputHelper() {
flush();
fclose(m_filePtr);
}
void precision(int prec) {
m_floatReserve = prec;
m_floatRatio = pow(10, prec);
m_tempBufDot = m_tempBuf + prec;
}
outputHelper<_BufferSize> &flush() {
fwrite(m_buf, 1, m_cursor - m_buf, m_filePtr);
fflush(m_filePtr);
m_cursor = m_buf;
return *this;
}
void putChar(const char &c) {
if (m_cursor == m_end) flush();
*m_cursor++ = c;
}
void putS(const char *c) {
while (*c) putChar(*c++);
}
template <typename _Tp, std::enable_if_t<std::is_signed_v<_Tp> & std::is_integral_v<_Tp>> * = nullptr>
outputHelper<_BufferSize> &operator<<(const _Tp &ret) {
_Tp _ret = _Tp(ret);
if (_ret >= 0) {
do {
*m_tempBufCursor++ = '0' + _ret % 10;
_ret /= 10;
} while (_ret);
do putChar(*--m_tempBufCursor);
while (m_tempBufCursor > m_tempBuf);
} else {
putChar('-');
do {
*m_tempBufCursor++ = '0' - _ret % 10;
_ret /= 10;
} while (_ret);
do putChar(*--m_tempBufCursor);
while (m_tempBufCursor > m_tempBuf);
}
return *this;
}
template <typename _Tp, std::enable_if_t<std::is_unsigned_v<_Tp> & std::is_integral_v<_Tp>> * = nullptr>
outputHelper<_BufferSize> &operator<<(const _Tp &ret) {
_Tp _ret = _Tp(ret);
do {
*m_tempBufCursor++ = '0' + _ret % 10;
_ret /= 10;
} while (_ret);
do putChar(*--m_tempBufCursor);
while (m_tempBufCursor > m_tempBuf);
return *this;
}
template <typename _Tp, std::enable_if_t<std::is_floating_point_v<_Tp>> * = nullptr>
outputHelper<_BufferSize> &operator<<(const _Tp &ret) {
if (ret < 0) {
putChar('-');
return *this << -ret;
}
_Tp _ret = ret * m_floatRatio;
uint64_t integer = _ret;
if (_ret - integer >= 0.4999999999) integer++;
do {
*m_tempBufCursor++ = '0' + integer % 10;
integer /= 10;
} while (integer);
if (m_tempBufCursor > m_tempBufDot) {
do putChar(*--m_tempBufCursor);
while (m_tempBufCursor > m_tempBufDot);
putChar('.');
} else {
putS("0.");
for (int i = m_tempBufDot - m_tempBufCursor; i--;) putChar('0');
}
do putChar(*--m_tempBufCursor);
while (m_tempBufCursor > m_tempBuf);
return *this;
}
outputHelper<_BufferSize> &operator<<(const char &ret) {
putChar(ret);
return *this;
}
outputHelper<_BufferSize> &operator<<(const std::string &ret) {
putS(ret.data());
return *this;
}
};
template <uint64_t _BufferSize, uint64_t _BlockSize>
inputHelper<_BufferSize, _BlockSize> &getline(inputHelper<_BufferSize, _BlockSize> &ih, std::string &ret) {
ret.clear();
if (ih.getChar_Checked() == EOF)
ih.setState(0);
else {
while (!inputHelper<_BufferSize, _BlockSize>::isEndline(ih.getChar_Checked())) {
ret += ih.getChar_Unchecked();
ih.next();
}
ih.next();
}
return ih;
}
template <typename D, typename T, typename... S>
void printLog(D delim, const T &x, S... rest) {
cout << x;
if constexpr (sizeof...(rest) > 0) {
cout << delim;
printLog(delim, rest...);
}
}
}
using OY::getline;
```
by Ruiqun2009 @ 2022-07-20 15:04:34
@[Ruiqun2009](/user/589895) 蒟蒻膜拜大神
by wyhnet @ 2022-07-20 15:10:01