1. 計算程序運行時間

#include <iostream>
#include <ctime>

int main() {
    clock_t start, end;
    start = clock();
    
    // 執行需要計時的代碼
    
    end = clock();
    double duration = double(end - start) / CLOCKS_PER_SEC;
    
    std::cout << "程序運行時間：" << duration << "秒" << std::endl;
    
    return 0;
}

2. 計算函數執行時間

#include <iostream>
#include <ctime>

void func() {
    clock_t start, end;
    start = clock();
    
    // 執行需要計時的代碼
    
    end = clock();
    double duration = double(end - start) / CLOCKS_PER_SEC;
    
    std::cout << "函數執行時間：" << duration << "秒" << std::endl;
}

int main() {
    func();
    
    return 0;
}

3. 計算兩個操作之間的時間間隔

#include <iostream>
#include <ctime>

int main() {
    clock_t start, end;
    start = clock();
    
    // 執行操作1
    
    end = clock();
    double duration1 = double(end - start) / CLOCKS_PER_SEC;
    
    start = clock();
    
    // 執行操作2
    
    end = clock();
    double duration2 = double(end - start) / CLOCKS_PER_SEC;
    
    std::cout << "操作1執行時間：" << duration1 << "秒" << std::endl;
    std::cout << "操作2執行時間：" << duration2 << "秒" << std::endl;
    
    return 0;
}