Question

我需要输入搜索数组的帮助。我尝试进行二分搜索，但我无法让它工作。其他一切正常，直到我把我在数组中搜索的值，然后它只是崩溃。

它如何工作：输入2坐标，每个坐标值然后它计算它们之间的距离然后它假设让用户在坐标中搜索值和状态，如果找到它所在的坐标。

由于

#include "stdafx.h"
#include <iostream>
#include <iomanip>  //for setprecision
#include <math.h>
#include <cstdbool>
#include <cstdlib>  // Needed for rand and srand
#include <ctime>    // Needed for the time function


using namespace std;


//Function Prototypes
void processThroughArray(int[][10][10], int, int, int, int, int, int);
int searchArray(int[][10][10], int, int, int, int, int, int, int, int);
const int SIZE = 10;

int main()
{

// establish array and set all values to 0
int myArray[10][10][10] = { 0 };

// establish x and y position markers
int x = 0;
int y = 0;
int z = 0;
int x2 = 0;
int y2 = 0;
int z2 = 0;


// establish input for x and y from the user
int xInput = 0;
int yInput = 0;
int zInput = 0;
int xInput2 = 0;
int yInput2 = 0;
int zInput2 = 0;

// variable for value entered
int inputValue = 0;
int inputValue2 = 0;
double distance = 0;
int searchValue;
int result;


// Get the user's value and coordinate
cout << "\nPlease enter the x coordinate ";
cin >> xInput;
cout << "\nPlease enter the y coordinate ";
cin >> yInput;
cout << "\nPlease enter the z coordinate ";
cin >> zInput;


cout << "\nPlease enter the value to place in " << xInput << "," << yInput << "," << zInput << " ";
cin >> inputValue;

// Get the user's ending value and coordinate
cout << "\nPlease enter the ending x coordinate ";
cin >> xInput2;
cout << "\nPlease enter the ending y coordinate ";
cin >> yInput2;
cout << "\nPlease enter the ending z coordinate ";
cin >> zInput2;


cout << "\nPlease enter the value to place in " << xInput2 << "," << yInput2 << "," << zInput2 << " ";
cin >> inputValue2;

// place the value in the coordinate
myArray[xInput][yInput][zInput] = inputValue;
cout << "\nYou have successfully placed the value " << inputValue << " in coordinate " << xInput << ", " << yInput << ", " << zInput << " ";

myArray[xInput2][yInput2][zInput2] = inputValue2;
cout << "\nYou have successfully placed the value " << inputValue2 << " in coordinate " << xInput2 << ", " << yInput2 << ", " << zInput2 << " ";

//Function performing for loop
processThroughArray(myArray, x, y, z, x2, y2, z2);

//calculate distance between the two coordinates
distance = sqrt(pow(xInput2 - xInput, 2.0) + pow(yInput2 - yInput, 2.0) + pow(zInput2 - zInput, 2.0));
cout << "\nThe distance between " << xInput << "," << yInput << "," << zInput << " and " << xInput2 << "," << yInput2 << "," << zInput2 << " is ";
cout << setprecision(4) << distance << endl;


// indicate end of array processing
cout << "\nArray Processed" << endl;

//User inputs value to search for
cout << "Enter the value you wish to look for: ";
cin >> searchValue;

result = searchArray(myArray, SIZE, searchValue, x, y, z, x2, y2,z2);

//If results contains a -1 the value not found

if (result == -1 )
{
    cout << "That number does not exists in the array.\n";
}

else 
{
    cout << "\nValue " << searchValue;
    cout << " is located at position: " << result << endl;

}




system("pause");
return 0;
}


//**************************************************************************
// Definition of function processThroughArray: Process through the array   *
//the for loop                                                             *
//**************************************************************************
void processThroughArray(int myArray[][10][10], int x, int y, int z, int x2, int y2, int z2)
{

for (int x = 0, x2 = 0; x<10, x2 < 10; x++, x2++)
{
    for (int y = 0, y2 = 0; y<10, y2 < 10; y++, y2++)

    {
        for (int z = 0, z2 = 0; z< 10, z2 < 10; z++, z2++)
        {

            // Display the value of the coordinate
            cout << "\nCordinate " << x << ", " << y << ", " << z << " value is " << myArray[x, x2][y, y2][z, z2];

        }
    }
}



}

//**************************************************************************
// Definition of function searchArray: search array for the value input    *
//                                                                         *
//**************************************************************************
int searchArray(int myArray[][10][10], int size, int value,int x, int y, int z, int x2, int y2, int z2)
{
int index = 0;
int position = -1;
bool found = false;


while (index < size && !found)
{
    if (myArray[index][index][index] == value)
    {
        found = true;
        position = index;

    }
    index++;

} 

return position;
}

Answer 1

您将SIZE定义为1000，并将其传递给searchArray（）：

const int SIZE = 1000;

// ...

searchArray(myArray, SIZE, searchValue);

您在searchArray（）中执行以下操作：

int searchArray(int myArray[][10][10], int size, int value)
{
    int first = 0,
        last = size - 1,

由于size为1000，因此您将“first”设置为0，将“last”设置为999.

然后，你正在做以下事情（遗漏一些无关紧要的东西）：

middle = (first + last) / 2;
if (myArray[middle][middle][middle] = value)

所以，我们拿出一张纸和一支铅笔。由于“first”为0，“last”为999，因此将“middle”设置为449。

所以，我们在这里有两个问题：

1）您使用“=”运算符进行分配，而不是使用“==”进行比较，这似乎是您的意图。

2）您正在为myArray [449] [449] [449]指定一个值。不幸的是，你的数组要小得多：

int myArray[10][10][10] = { 0 };

尝试访问十个元素的第449个数组的第449个元素，即十个元素的十个数组的第449个数组中的第449个元素，并不能很好地工作。即使您正在比较或分配某些内容，无论哪种方式，这都是未定义的行为，并且几乎可以保证崩溃。

搜索3d数组

1 个答案: