C ++中的距离公式 [英] Distance Formula in C++

问题描述

您好，

在我的代码中，我试图找到两点之间的距离

（X1，Y1）& （X2，Y2）

这些数字来自代码的第一部分

我正确地获得了第一个距离，但它不断重复，我不知道为什么

任何建议都表示赞赏

Hello,
In my code I’m trying to find the distance between two points
(X1,Y1) & (X2,Y2)
These numbers are generating from the first part of the code
I got the first distance correctly but its keep repeating itself , I don’t know why
Any suggestion is appreciated

#include <iostream>
#include <string>
#include <fstream>
#include <cmath>

using namespace std;


int main()
{
                  /// generating 100 point, find x,y for each point///
	int  Radio_Range=80 ,No_Max=100 ;
	int  x, y ;
	int  Total_Degree=0;
	int GridF[100][2];
	ofstream  myfile;  
	myfile.open ("example.txt");  
	int row=0;
	int miny=0,max_y=99;
	for(int i=0;i<5;i++)
	{
		int minx=0,max_x=99;
		for(int j=0;j<5;j++)
		{
			for(int k=0;k<4;k++)
			{
				x= minx+rand()%(max_x - minx+1);
				y= miny+rand()%(max_y - miny+1);

				GridF[row][0]= x;
				GridF[row][1]= y;

				

				cout<<GridF[row][0]<<"  "<<GridF[row][1]<<endl;
				
				myfile<<GridF[row][0]<<"  "<<GridF[row][1]<<endl;
				
			
			}
			minx=max_x+1;
			max_x=max_x+100;
		}
		miny=max_y+1;
		max_y=max_y+100; 
	} 
		



/////////////////// Find the distance btw 2 points///////////

	double result ,xGrid,yGrid;
	int DistanceCounter=0;	
	cout<<"Distance : "<<endl;
	cout<<endl;
	
	for(int i=0;i<50;i++)
	{
	for(int j=0;j<2;j++)
	{
 
	
//xresult
		xGrid=(GridF[j+1][0] - GridF[j][j]);?????????????
		xGrid=abs(xGrid); xGrid=xGrid*xGrid;
		cout<<"xGrid="<<xGrid<<endl;
//yresult
		
		yGrid=(GridF[j+1][j+1] - GridF[j][j+1]);?????????
		yGrid=abs(yGrid); yGrid=yGrid*yGrid;
		cout<<"yGrid="<<yGrid<<endl;
////result
		result = xGrid + yGrid;
		result = sqrt (result);
		cout<<"Equation : "<<result<<endl;
	
		
	}
	
	}

	}

我想问题发生在GridF [] [] // 2D数组中，是不是正确的方法？

I thik the problem occur in GridF[][]// 2D array, is it the right way ??

推荐答案

有趣的代码。我无法找到您更改行变量的位置。它看起来总是保持为0.在这种情况下，您首先将tripple-nested循环总是将值分配给GridF [0] [0]和GridF [0] [1]元素，如连续5000次，保留所有其他元素未分配。我可以很容易地修复你的代码，但请先尝试自己修复它并让我们知道结果

Interesting code. I can''t find where you change your row variable. It looks like it always stays as 0. In this case you first tripple-nested loop always assigns values to GridF[0][0] and GridF[0][1] elements like 5000 times in a row, leaving all other elements unassigned. I can easily fix your code, but please try to fix it yourself first and let us know about the results

第一个问题，已经解释过的是缺少的行变量。

然而，第二部分是类似的，关于代码的第二部分...



你的第二个循环使用我从0到49， j 从0到1。您只能使用 j + 1 访问 GridF 。因此， xGrid 和 yGrid 始终访问相同的索引（1） - 导致相同的值。



作为概念证明，你应该有一个0-99的单循环，并使用单个变量访问数组索引。如果代码是生产代码的精简版本，则必须使用 i GridF 数组>和 j 。



我看到第三个问题，你的数组有100个值，但循环为我只能达到50.



概念证明解决方案如下：

The first issue, as already explained is the missing row variable.
However, the second is of a similar ilk, regarding the second part of the code...

Your second loop uses i from 0-49 and j from 0-1. You are only accessing GridF with j + 1. As a result xGrid and yGrid are always accessing the same index (1) - resulting in identical values.

As a "proof of concept", you should really have a single loop from 0-99 and access the array index using a single variable. If the code is a stripped down version of production code, then you must access the GridF array using a operation of both i and j.

I see a third problem in that your array has 100 values, but the loop for i only reaches 50.

A "proof of concept" solution would be the following:

for (int i = 1; i < 100; ++i)
{
  xGrid = abs(GridF[i][0] - GridF[i - 1][0]);
  xGrid *= xGrid;
  cout << "xGrid=" << xGrid << endl;

  yGrid = abs(GridF[i][1] - GridF[i - 1][1]);
  yGrid *= yGrid;
  cout << "yGrid=" << yGrid << endl;

  result = sqrt(xGrid + yGrid);
  cout << "Equation : " << result << endl;
}

另请注意显而易见的事实：

1）您将获得99个输出，不是100，

2）没有验证（如果min-max值需要的话），

3）双int转换的考虑。

Also note the obvious facts:
1) You will get 99 outputs, not 100,
2) There is no validation (if required for min-max values),
3) Consideration for the double-int casting.

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