本文共 1751 字，大约阅读时间需要 5 分钟。

时间复杂度_函数传参、传引用、传指针

实验开始：

#include 
   
    #include 
    
     #include 
     
      using namespace std;#define NODE_SIDE 1000  // 1000~1000000time_t startTime, endTime;struct Node{    int num[NODE_SIDE];};void testByValue(Node a){}void testByReference(Node &a){}void testByPointer(Node *a){}int main(){    long long int TEST_TIME;    Node n;    n.num[0] = 0;  //why    int i;    for(int j = 1; j <= 1000; j *= 10)  //enlarge TEST_TIME    {        TEST_TIME = 1000000 * j;        i = TEST_TIME;        startTime = clock();        while(i--)        {            testByValue(n);        }        endTime = clock();        cout << "TestByvalue:     NODE_SIDE(" << setw(7) << NODE_SIDE << "), TEST_TIME(" << setw(10) << TEST_TIME << "), cost :" << setw(7) << (endTime - startTime) << " ms." << endl;        i = TEST_TIME;        startTime = clock();        while(i--)        {            testByReference(n);        }        endTime = clock();        cout << "TestByReference: NODE_SIDE(" << setw(7) << NODE_SIDE << "), TEST_TIME(" << setw(10) << TEST_TIME << "), cost :" << setw(7) << (endTime - startTime) << " ms." << endl;        i = TEST_TIME;        startTime = clock();        while(i--)        {            testByPointer(&n);        }        endTime = clock();        cout << "TestByPointer:   NODE_SIDE(" << setw(7) << NODE_SIDE << "), TEST_TIME(" << setw(10) << TEST_TIME << "), cost :" << setw(7) << (endTime - startTime) << " ms." << endl;    }    return 0;}
     
    
   

条件：NODE_SIZE为1000，实验环境为MinGW。（最后的结果 ms并未除以CLOCK_PER_SEC， 不同机器结果可能会有细小的差异。）

某一次的运行结果：