使用字符串數組而不是int數組實現二進制搜索

Question

該程序應該將其合並到其中。 我創建了大部分代碼，但這是實驗的第二部分，我必須返回並輸入用於二進制搜索的字符串。 如果必須刪除idNum以及結果和empId，我不會得到如何搜索字符串的信息。

    const int NUM_NAMES = 20;
       string names[NUM_NAMES] = {"Collins, Bill", "Smith, Bart", "Allen, Jim",
                                   "Griffin, Jim", "Stamey, Marty", "Rose, Geri",
                                   "Taylor, Terri", "Johnson, Jill", "Allison, Jeff",
                                   "Looney, Joe", "Wolfe, Bill", "James, Jean",
                                   "Weaver, Jim", "Pore, Bob", "Rutherford, Greg",
                                   "Javens, Renee", "Harrison, Rose", "Setzer, Cathy",
                                   "Pike, Gordon", "Holland, Beth" };

因此，二進制搜索將使用字符串而不是int。 我不知道該怎么做。

    // Function prototype
    int binarySearch(const int [], int, int);
    const int SIZE = 20;

    int main()
    {

        // Array with employee IDs sorted in ascending order.
       int idNums[SIZE] = {101, 142, 147, 189, 199, 207, 222,
                           234, 289, 296, 310, 319, 388, 394,
                           417, 429, 447, 521, 536, 600};
       int results;   // To hold the search results
       int empID;     // To hold an employee ID

       // Get an employee ID to search for.
       cout << "Enter the employee ID you wish to search for: ";
       cin >> empID;

       // Search for the ID.
       results = binarySearch(idNums, SIZE, empID);

       // If results contains -1 the ID was not found.
       if (results == -1)
          cout << "That number does not exist in the array.\n";
       else
       {
          // Otherwise results contains the subscript of
          // the specified employee ID in the array.
          cout << "That ID is found at element " << results;
          cout << " in the array.\n";
       }
       return 0;
    }

binarySearch函數對整數數組執行二進制搜索。 搜索具有最大大小元素的數組，以查找存儲在value中的數字。 如果找到該數字，則返回其數組下標。 否則，返回-1，指示值不在數組中。

int binarySearch(const int array[], int size, int value)
{
   int first = 0,             // First array element
       last = size - 1,       // Last array element
       middle,                // Mid point of search
       position = -1;         // Position of search value
   bool found = false;        // Flag

   while (!found && first <= last)
   {
      middle = (first + last) / 2;     // Calculate mid point
      if (array[middle] == value)      // If value is found at mid
      {
         found = true;
         position = middle;
      }
      else if (array[middle] > value)  // If value is in lower half
         last = middle - 1;
      else
         first = middle + 1;           // If value is in upper half
   }
   return position;
}

Answer 1

更改

int binarySearch(const int array[], int size, int value)

至

int binarySearch(const std::string array[], int size, const std::string &value)

然后如下使用它

std::string name;
std::getline(std::cin, name); // read name from console
std::sort(names, names + NUM_NAMES); // make sure the array is sorted
results = binarySearch(names, NUM_NAMES, name);

您還可以使用模板，以便您的代碼更通用

template<typename T>
int binarySearch(const T array[], int size, const T &value)