一些-study项目中有用的代码片段
[C++]生成GUID(仅Windows下可用)
#include <objbase.h>
GUID CreateGuid() {
GUID guid;
if (CoCreateGuid(&guid) == S_OK) {
return guid;
}
throw exception("generate guid failed!");
}
string GuidToString(const GUID& guid) {
char buf[64] = { 0 };
snprintf(buf, sizeof(buf),
"{%08X-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X}",
guid.Data1, guid.Data2, guid.Data3,
guid.Data4[0], guid.Data4[1], guid.Data4[2], guid.Data4[3],
guid.Data4[4], guid.Data4[5], guid.Data4[6], guid.Data4[7]);
return string(buf);
}
[C++]高斯消元
#include <vector>
class Matrix : public std::vector<std::vector<double> > {
public:
void Init(int row, int col) {
assign(row, vector<double>());
for (int i = 0; i < row; i++) {
at(i).assign(col, 0);
}
}
};
/*要求系数矩阵可逆
此处A为增广矩阵，即A[i][n]为第i个方程右边的常数bi
运行结束后A[i][n]为第i个未知数的值 */
void gauss_elimination(std::vector<std::vector<double> >& A, int n) {
int i, j, k, r;
//消元过程
for (i = 0; i < n; i++) {
//选一行r并与第i行交换
r = i;
for (j = i + 1; j < n; j++) {
if (fabs(A[j][i]) > fabs(A[r][i])) {
r = j;
}
}
if (r != i) {
for (j = 0; j <= n; j++) {
std::swap(A[r][j], A[i][j]);
}
}
//与第i+1至第n行进行消元
for (k = i + 1; k < n; k++) {
double f = A[k][i] / A[i][i];
for (j = i; j <= n; j++) {
A[k][j] -= f * A[i][j];
}
}
}
//回代过程
for (i = n - 1; i >= 0; i--) {
for (j = i + 1; j < n; j++) {
A[i][n] -= A[j][n] * A[i][j];
}
A[i][n] /= A[i][i];
}
}
[C++]多项式拟合
#include <iostream>
// 高斯消元，定义在上一节
void gauss_elimination(std::vector<std::vector<double> >& A, int n)
inline bool fequal(double a, double b) {
return fabs(a - b) < 1e-6;
}
void fxformatprint(std::vector<std::vector<double> > a, int n) {
bool first = 1;
int last = 0;
std::cout << std::fixed << "f(x)=";
for (int i = 0; i < n; i++) {
if (fequal(a[i][n], 0)) {
continue;
}
last = i;
if (a[i][n] > 0 && !first) {
std::cout << '+';
}
if (!fequal(a[i][n], 1)) {
if (fequal(a[i][n], -1)) {
std::cout << '-';
}
else {
std::cout << a[i][n];
}
}
if (n - (i + 1) > 1) {
std::cout << "x^" << n - (i + 1);
}
else if (n - (i + 1) == 1) {
std::cout << "x";
}
first = 0;
}
if (fequal(a[last][n], -1)) {
std::cout << 1;
}
}
// 仅支持{(1, a1),(2, a2),...,(n, an)}的数据
int main() {
std::vector<std::vector<double> > a;
int n;
std::cin >> n;
a.assign(row, vector<double>());
for (int i = 0; i < row; i++) {
a.at(i).assign(col, 0);
}
for (int i = 0; i < n; i++) {
std::cin >> a[i][n];
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
a[i][j] = pow(i + 1, n - (j + 1));
}
}
// 高斯消元
gauss_elimination(a, n);
// 多项式输出
fxformatprint(a, n);
return 0;
}
[C++]斗地主牌型解析(?)
const int CardTypeCount = 13;
enum CardType {
Single,
Double,
Triple,
TripleSingle,
TripleDouble,
Straight,
DoubleStraight,
TripleStraight,
PlaneWithSingle,
PlaneWithDouble,
Bomb,
SuperBomb,
BombDouble,
};
std::map<std::multiset<int>, CardType> CardTypeMap{
{std::multiset<int>({4}),CardType::Bomb},
{std::multiset<int>({4,2}),CardType::BombDouble},
{std::multiset<int>({3}),CardType::Triple},
{std::multiset<int>({3,1}),CardType::TripleSingle},
{std::multiset<int>({3,2}),CardType::TripleDouble},
{std::multiset<int>({3,3}),CardType::TripleStraight},
{std::multiset<int>({3,3,3}),CardType::TripleStraight},
{std::multiset<int>({3,3,3,3}),CardType::TripleStraight},
{std::multiset<int>({3,3,3,3,3}),CardType::TripleStraight},
{std::multiset<int>({3,3,1,1}),CardType::PlaneWithSingle},
{std::multiset<int>({3,3,3,1,1,1}),CardType::PlaneWithSingle},
{std::multiset<int>({3,3,2,2}),CardType::PlaneWithDouble},
{std::multiset<int>({3,3,3,2,2,2}),CardType::PlaneWithDouble},
{std::multiset<int>({2}),CardType::Double},
{std::multiset<int>({2,2,2}),CardType::DoubleStraight},
{std::multiset<int>({2,2,2,2}),CardType::DoubleStraight},
{std::multiset<int>({2,2,2,2,2}),CardType::DoubleStraight},
{std::multiset<int>({2,2,2,2,2,2}),CardType::DoubleStraight},
{std::multiset<int>({2,2,2,2,2,2,2}),CardType::DoubleStraight},
{std::multiset<int>({2,2,2,2,2,2,2,2}),CardType::DoubleStraight},
{std::multiset<int>({1}),CardType::Single},
{std::multiset<int>({1,1}),CardType::Double},
{std::multiset<int>({1,1,1,1,1}),CardType::Straight},
{std::multiset<int>({1,1,1,1,1,1}),CardType::Straight},
{std::multiset<int>({1,1,1,1,1,1,1}),CardType::Straight},
{std::multiset<int>({1,1,1,1,1,1,1,1}),CardType::Straight},
{std::multiset<int>({1,1,1,1,1,1,1,1,1}),CardType::Straight},
{std::multiset<int>({1,1,1,1,1,1,1,1,1,1}),CardType::Straight},
{std::multiset<int>({1,1,1,1,1,1,1,1,1,1,1}),CardType::Straight},
{std::multiset<int>({1,1,1,1,1,1,1,1,1,1,1,1}),CardType::Straight},
{std::multiset<int>({1,1,1,1,1,1,1,1,1,1,1,1,1}),CardType::Straight},
};
class CardToken {
private:
std::string BaseString;
CardType Type;
template<class T>
std::multiset<std::pair<int, T>> Count(std::vector<T> v) {
constexpr int tmpsize = std::numeric_limits<T>::max() - std::numeric_limits<T>::min();
int tmp[tmpsize];
memset(tmp, 0, sizeof(tmp));
for (int i = 0; i < v.size(); i++) {
tmp[v[i]]++;
}
std::multiset<pair<int, T>> ans;
for (int i = 0; i < tmpsize; i++) {
if (tmp[i] != 0) {
ans.insert(pair<int, T>(tmp[i], i));
}
}
return ans;
}
template<class T>
CardType GetCardTypeByCountResult(std::multiset<std::pair<int, T>> CountResult) {
std::multiset<int> times, cards;
for (typename std::multiset<std::pair<int, T>>::const_iterator iter = CountResult.begin(); iter != CountResult.end(); iter++) {
times.insert(iter->first);
cards.insert(iter->second);
}
CardType ans = CardTypeMap[times];
if (ans == CardType::Double && cards.count('S') && cards.count('L')) {
ans = CardType::SuperBomb;
}
return ans;
}
public:
CardToken(std::string BaseString) :BaseString(BaseString) {};
CardToken() { BaseString = ""; }
CardType GetCardType()const { return Type; }
void SetCardType(CardType Type) {
if (Type >= CardTypeCount || Type < 0) {
throw "CardType undefined!";
}
this->Type = Type;
}
std::string GetBaseString()const { return BaseString; }
void SetBaseString(const std::string& BaseString) {
this->BaseString = BaseString;
this->Type = GetCardTypeByCountResult(Count(std::vector<char>(BaseString.begin(), BaseString.end())));
}
};
//3-10(X is 10),JQK,small and large king
//const std::string SortedCards = "3456789XJQK12SL";
[C++]分数类
#pragma once
#include <sstream>
template<class Integer>
class FractionBase {
private:
inline const Integer& gcd(const Integer& a, const Integer& b) {
return b > 0 ? gcd(b, a % b) : a;
}
inline const Integer& lcm(const Integer& a, const Integer& b) {
return a * b / gcd(a, b);
}
inline const Integer& pow(const Integer& a, int b) {
Integer result = 1;
for (int i = 1; i <= b; i++) {
result *= a;
}
return result;
}
inline int GetDecimalLength(double a) {
std::stringstream ss;
ss << a - (int)a;
return ss.str().length() - 2;
}
inline int GetDecimalLength(long double a) {
std::stringstream ss;
ss << a - (int)a;
return ss.str().length() - 2;
}
inline void Simplify() {
Integer gcdValue = gcd(numerator, denominator);
numerator /= gcdValue;
denominator /= gcdValue;
}
Integer numerator, denominator;
public:
FractionBase(const Integer& numerator, const Integer& denominator):
numerator(numerator), denominator(denominator) {
Simplify();
}
FractionBase(double a) {
(*this) = a;
}
FractionBase(long double a) {
(*this) = a;
}
FractionBase(const Integer& a) {
(*this) = a;
}
FractionBase() { }
// 获取分子
Integer& GetNumerator() { return numerator; }
// 获取分母
Integer& GetDenominator() { return denominator; }
// 获取倒数
inline FractionBase GetReversed() { return FractionBase(denominator, numerator); }
void SetNumerator(Integer numerator) {
this->numerator = numerator;
}
void SetDenominator(Integer deno) {
if (deno == 0) {
throw "The denominator cannot be 0!";
}
denominator = deno;
//std::cout << denominator << ' ' << deno << std::endl;
}
FractionBase& operator=(FractionBase a) {
numerator = a.numerator;
denominator = a.denominator;
Simplify();
return *this;
}
FractionBase& operator=(const Integer& a) {
SetNumerator(a);
SetDenominator(1);
Simplify();
return *this;
}
FractionBase& operator=(double a) {
int DecimalLength = GetDecimalLength(a);
SetNumerator(a * pow(10, DecimalLength));
SetDenominator(pow(10, DecimalLength));
Simplify();
return *this;
}
FractionBase& operator=(long double a) {
int DecimalLength = GetDecimalLength(a);
SetNumerator(a * pow(10, DecimalLength));
SetDenominator(pow(10, DecimalLength));
Simplify();
return *this;
}
friend FractionBase operator+(FractionBase& a, FractionBase& b) {
return FractionBase(a.GetNumerator() * b.GetDenominator() + a.GetDenominator() * b.GetNumerator(), a.GetDenominator() * b.GetDenominator());
}
friend FractionBase operator-(FractionBase& a, FractionBase& b) {
return FractionBase(a.GetNumerator() * b.GetDenominator() - a.GetDenominator() * b.GetNumerator(), a.GetDenominator() * b.GetDenominator());
}
friend FractionBase operator*(FractionBase& a, FractionBase& b) {
return FractionBase(a.GetNumerator() * b.GetNumerator(), a.GetDenominator() * b.GetDenominator());
}
friend FractionBase operator/(FractionBase& a, FractionBase& b) {
return a * b.GetReversed();
}
friend FractionBase& operator+=(FractionBase& a, const FractionBase& b) { return a = a + b; }
friend FractionBase& operator-=(FractionBase& a, const FractionBase& b) { return a = a - b; }
friend FractionBase& operator*=(FractionBase& a, const FractionBase& b) { return a = a * b; }
friend FractionBase& operator/=(FractionBase& a, const FractionBase& b) { return a = a / b; }
friend bool operator>(const FractionBase& a, const FractionBase& b) {
return a.GetNumerator() * b.GetDenominator() > a.GetDenominator() * b.GetNumerator();
}
friend bool operator<(const FractionBase& a, const FractionBase& b) {
return a.GetNumerator() * b.GetDenominator() < a.GetDenominator() * b.GetNumerator();
}
friend bool operator==(const FractionBase& a, const FractionBase& b) {
return a.GetNumerator() == b.GetNumerator() && a.GetDenominator() == b.GetDenominator();
}
friend bool operator>=(const FractionBase& a, const FractionBase& b) {
return a > b || a == b;
}
friend bool operator<=(const FractionBase& a, const FractionBase& b) {
return a < b || a == b;
}
friend bool operator!=(const FractionBase& a, const FractionBase& b) {
return !(a == b);
}
template<class T>
friend std::ostream& operator<<(std::ostream& os, FractionBase<T> a);
template<class T>
friend std::istream& operator>>(std::istream& is, FractionBase<T>& a);
};
template<class Integer>
std::ostream& operator<<(std::ostream& os, FractionBase<Integer> a) {
return os << a.GetNumerator() << '/' << a.GetDenominator();
}
template<class Integer>
std::istream& operator>>(std::istream& is, FractionBase<Integer>& a) {
Integer numerator, denominator;
is >> numerator >> denominator;
a.SetNumerator(numerator);
a.SetDenominator(denominator);
return is;
}
typedef FractionBase<int> frac;
[C++]随机数生成器类(梅森旋转法)
从一个实际项目中抽出来的 所以使用了functional
#pragma once
#include <functional>
#include <ctime>
class Random
{
private:
int MTindex;
long long MT[624];
void csrand(int seed) {
MTindex = 0;
MT[0] = seed;
for (int i = 1; i < 624; i++) {
int t = 1812433253 * (MT[i - 1] ^ (MT[i - 1] >> 30)) + i;
MT[i] = t & 0xffffffff;
}
}
inline void generate() {
for (int i = 0; i < 624; i++) {
long long y = (MT[i] & 0x80000000) + (MT[(i + 1) % 624] & 0x7fffffff);
MT[i] = MT[(i + 397) % 624] ^ (y >> 1);
if (y % 2 == 1) MT[i] ^= 2147483647;
}
}
public:
std::function<int()> RandInt = [this] {
if (MTindex == 0) generate();
int y = MT[MTindex];
y = y ^ (y >> 11);
y = y ^ ((y << 7) & 1636928640);
y = y ^ ((y << 15) & 1022730752);
y = y ^ (y >> 18);
MTindex = (MTindex + 1) % 624;
return y;
};
std::function<int(int, int)> RandIntEx = [this](int Min, int Max) {
if (Min > Max) Min = Max;
if (Min == Max) return Min;
else return RandInt() % (Max - Min + 1) + Min;
};
std::function<long long()> RandLongLong = [this] {
return ((long long)(RandInt()) << 31) + RandInt();
};
std::function<long long(long long, long long)> RandLongLongEx = [this](long long Min, long long Max) {
if (Min > Max) Min = Max;
if (Min == Max) return Min;
else return RandLongLong() % (Max - Min + 1) + Min;
};
std::function<bool()> RandBool = [this] {
return RandIntEx(0, 1);
};
std::function<char()> RandVisibleChar = [this] {
return RandIntEx(32, 126);
};
std::function<char()> RandUpperLetter = [this] {
return RandIntEx('A', 'Z');
};
std::function<char()> RandLowerLetter = [this] {
return RandIntEx('a', 'z');
};
std::function<char()> RandLetter = [this] {
return RandBool() ? RandUpperLetter() : RandLowerLetter();
};
std::function<char()> RandFormatChar = [this] {
const char fmtc[5] = { '\n','\t','\r','\v','\f' };
return fmtc[RandIntEx(0, 4)];
};
std::function<std::string(int)> RandWord = [this](int Length) {
std::string result = "";
for (int i = 0; i < Length; i++) {
result = result + RandLetter();
}
return result;
};
std::function<std::string(int, int, int)> RandArticle = [this](int WordSum, int WordLengthMin = 1, int WordLengthMax = 10) {
std::string result;
result = RandWord(RandIntEx(WordLengthMin, WordLengthMax));
for (int i = 1; i < WordSum; i++) {
result = result + " " + RandWord(RandIntEx(WordLengthMin, WordLengthMax));
}
return result;
};
Random() {
csrand((int)time(NULL));
}
~Random() {
}
};