#include <iostream> void BubbleSort (int list[], int n){ for(int i = 0; i < n -1; i ++){ for(int j = 0; j < n-i-1; j++){ if(list[j] > list[j+1]) // 生序 0 1 2 3 4 5 6 7 8 9 //if(list[j] < list[j+1]) // 逆序列 9 8 7 6 5 4 3 2 1 0 std::swap(list[j], list[j+1]); } } } //Data structures and Algorithm Analysis in c++ 4th edition p14 class IntCell{ public: explicit IntCell(int initialValue = 0); int read() const; void write(int x); private: int storedValue; };
IntCell::IntCell(int initialValue) : storedValue{initialValue}{ }
int IntCell::read() const{ return storedValue; }
void IntCell::write(int x){ storedValue = x; }
int main(){ int a [] {0, 2, 4, 6, 8, 1, 3, 5 ,7, 9}; BubbleSort(a, 10); for(int k = 0; k < 10; k++){ std::cout << a[k] << ' '; } std::cout << std::endl; IntCell m; m.write(5); std::cout << "Cell contents: " << m.read() <<std::endl; return 0; }
*/ #include <iostream> #include <chrono> #include <iomanip> #include <ctime> #include <ratio> #include <cmath> using namespace std::chrono; int getRandom(int min, int max) { return (rand() % static_cast<int>(max + 1 - min)) + min; }
int main() { //professional c++ 4th edition p466 duration<long, std::ratio<60>> d1(123); std::cout << d1.count() << std::endl; duration<double> d2; d2 = d2.max(); std::cout << d2.count() << std::endl; duration<long, std::ratio<60>> d3(10); // = 10 minutes duration<long, std::ratio<1>> d4(14); // = 14 seconds
// Compare both durations if (d3 > d4) std::cout << "d3 > d4" << std::endl; else std::cout << "d3 <= d4" << std::endl;
// Increment d4 with 1 resulting in 15 seconds ++d4;
// Multiply d4 by 2 resulting in 30 seconds d4 *= 2; // duration<double, std::ratio<1>> d5 = d3 + d4; // 10 minutes + 30 seconds = 630 minutes or 630 seconds
duration<double, std::ratio<60>> d5 = d3 + d4; duration<long, std::ratio<1>> d6 = d3 + d4; std::cout << d3.count() << " minutes + " << d4.count() << " seconds = " << d5.count() << " minutes or " << d6.count() << " seconds" << std::endl; duration<long> d7(30);
// Convert the seconds of d7 to minutes duration<double, std::ratio<60>> d8(d7); std::cout << d7.count() << " seconds = " << d8.count() << " minutes" << std::endl;
// Convert the seconds of d7 to integral minutes using duration_cast() auto d8_ = duration_cast<duration<long, std::ratio<60>>>(d7); // minutes std::cout << d8_.count() << std::endl;
// Convert integral minutes to integral seconds duration<long, std::ratio<60>> d9(10); // minutes //minutes d9(10); // minutes duration<long> d10(d9); // seconds std::cout << d10.count() << std::endl;
// Use predefined durations auto t1 = hours(1) + minutes(23) + seconds(45); std::cout << seconds(t1).count() << " seconds" << std::endl;
// Standard user-defined literals auto myDuration = 42min; // 42 minutes //professional c++ 4th edition p468 // Get current time as a time_point system_clock::time_point tpoint = system_clock::now(); // Convert to a time_t time_t tt = system_clock::to_time_t(tpoint); // Convert to local time tm* t2 = std::localtime(&tt); // Write the time to the console std::cout << std::put_time(t2, "%H:%M:%S") << std::endl; // Convert to readable format char buffer[80] = { 0 }; strftime(buffer, sizeof(buffer), "%H:%M:%S", t2); // Write the time to the console std::cout << buffer << std::endl; //professional c++ 4th edition p469 auto start = high_resolution_clock::now(); // Execute code that you want to time double d = 0; for (int i = 0; i < 1000000; ++i) { d += sqrt(sin(i) * cos(i)); } // Get the end time and calculate the difference auto end = high_resolution_clock::now(); auto diff = end - start; // Convert the difference into milliseconds and output to the console std::cout << duration<double, std::milli>(diff).count() << "ms" << std::endl;
// Output d, because otherwise a compiler might optimize away the whole loop above. std::cout << d << std::endl; time_point<steady_clock> tp1; tp1 += minutes(10); // Store the duration between epoch and time_point auto d11 = tp1.time_since_epoch(); // Convert the duration to seconds and output to the console duration<double> d12(d11); std::cout << d12.count() << " seconds" << std::endl; { time_point<steady_clock, seconds> tpSeconds(42s); // Convert seconds to milliseconds implicitly. time_point<steady_clock, milliseconds> tpMilliseconds(tpSeconds);
std::cout << tpMilliseconds.time_since_epoch().count() << " ms" << std::endl; }
{ time_point<steady_clock, milliseconds> tpMilliseconds(42'424ms); // Convert milliseconds to seconds explicitly. time_point<steady_clock, seconds> tpSeconds( time_point_cast<seconds>(tpMilliseconds));
// Convert seconds back to milliseconds and output the result. milliseconds ms(tpSeconds.time_since_epoch()); std::cout << ms.count() << " ms" << std::endl; } //professional c++ 4th edition p470 srand(static_cast<unsigned int>(time(nullptr))); std::cout << rand() << std::endl;
std::cout << getRandom(1, 6) << std::endl;
return 0; }
/* wannian07@wannian07-PC:~$ g++ -std=c++17 -o c13 c13.cpp wannian07@wannian07-PC:~$ ./c13 123 1.79769e+308 d3 > d4 10 minutes + 30 seconds = 10.5 minutes or 630 seconds 30 seconds = 0.5 minutes 0 600 5025 seconds
21:07:05 21:07:05
108.155ms -nan
600 seconds
42000 ms 42000 ms
1647843756 3 */
