How to achieve optimal execution time of C++ functions?

Tips for optimizing the optimal execution time of C functions: avoid copy operations. Use inline functions. Use fast algorithms. Optimize data structures. Optimize memory usage.

How to achieve optimal execution time of C functions

Optimizing function execution time is the key to improving code efficiency. In C, optimal execution time can be achieved through the following techniques:

1. Avoid copy operations

Copy operations consume a lot of system resources. If possible, try to use a reference or pointer to access an object rather than creating a copy of it.

Practical case:

// 避免拷贝操作
void function(const MyClass& object) {
  // ...
}

2. Using inline functions

Can be avoided by declaring small functions as inline functions The cost of function calls. The compiler inserts the code for an inline function directly into the location where it is called.

Practical case:

// 内联函数
inline int add(int a, int b) {
  return a + b;
}

3. Use fast algorithm

For some common tasks, there is a higher performance algorithm. For example, using binary search instead of linear search can significantly improve search speed.

Practical case:

// 使用二分查找查找元素
int binary_search(int* array, int n, int target) {
  int low = 0, high = n - 1;
  while (low <= high) {
    int mid = (low + high) / 2;
    if (array[mid] == target) {
      return mid;
    } else if (array[mid] < target) {
      low = mid + 1;
    } else {
      high = mid - 1;
    }
  }
  return -1;
}

4. Optimize data structure

Selecting the appropriate data structure is crucial to improving performance . For example, using a hash table to find an element is much faster than searching an array.

Practical case:

// 使用哈希表查找元素
unordered_map<int, string> my_map;
string value = my_map[key];

5. Optimize memory usage

Excessive memory allocation and release will cause performance problems . Try to allocate larger memory blocks at once and release them gradually as needed.

Practical case:

// 一次性分配内存
int* my_array = new int[1000];
// 逐步释放内存
delete[] my_array;

By applying these techniques, the execution time of C functions can be significantly improved, thus improving the overall performance of the application.

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