检查给定点是否在任何给定塔的范围内

给定一个由{X _i , Y _i , R _i }形式的N行组成的二维数组arr[][]使得(X _i , Y _i )表示塔的位置， R _i表示塔的网络范围塔。给定两个整数X和Y ，任务是检查点(X, Y) 是否在塔的网络范围内。

例子：

Input: arr[][] = { {1, 1, 3}, {10, 10, 5}, {15, 15, 15} }, X = 5, Y = 5 
Output: True 
Explanation: 
Distance of point(5, 5) from (arr[0][0], arr[0][1]) = 5.65685 and the range of first tower is 3. Therefore, the point(X, Y) does not lie in the network-range of the first tower. 
Distance of point(5, 5) from (arr[1][0], arr[1][1]) = 7.07107 and the range of second tower is 5. Therefore, the point(X, Y) does not lie in the network-range of the second tower. 
Distance of point(5, 5) from (arr[2][0], arr[2][1]) = 14.1421 and the range of third tower is 15. Therefore, the point(X, Y) lies in the network-range of the third tower. 
Since, point (X, Y) lies in the range of the third tower. Therefore, the required output is True. 

Input: arr[][] = { {1, 1, 3}, {10, 10, 3}, {15, 15, 3} }, X = 5, Y = 5 
Output: False

方法：按照下面给出的步骤解决问题：

• 遍历数组，对于遍历的每一行(塔)，检查sqrt((arr[i][0] – x) ² + (arr[i][1] – Y) ² ) 的值是否大于arr[ i][2]与否。如果发现为真，则打印True 。
• 否则，打印False 。

C++

// C++ program to implement
// the above approach
 
#include 
using namespace std;
 
// Function to check if the point (X, Y)
// exists in the towers network-range or not
bool checkPointRange(int arr[][3], int X,
                     int Y, int N)
{
 
    // Traverse the array arr[]
    for (int i = 0; i < N; i++) {
 
        // Stores distance of the
        // point (X, Y) from i-th tower
        double dist
            = sqrt((arr[i][0] - X) * (arr[i][0] - X)
                   + (arr[i][1] - Y) * (arr[i][1] - Y));
 
        // If dist lies within the
        // range of the i-th tower
        if (dist <= arr[i][2]) {
            return true;
        }
    }
 
    // If the point (X, Y) does not lie
    // in the range of any of the towers
    return false;
}
 
// Driver Code
int main()
{
 
    int arr[][3] = { { 1, 1, 3 },
                     { 10, 10, 3 },
                     { 15, 15, 15 } };
    int X = 5, Y = 5;
 
    int N = sizeof(arr) / sizeof(arr[0]);
 
    // If point (X, Y) lies in the
    // range of any of the towers
    if (checkPointRange(arr, X, Y, N)) {
        cout << "True";
    }
    // Otherwise
    else {
        cout << "False";
    }
}

Java

// Java program to implement
// the above approach
import java.util.*;
 
class GFG{
  
// Function to check if the point (X, Y)
// exists in the towers network-range or not
static boolean checkPointRange(int arr[][], int X,
                               int Y, int N)
{
     
    // Traverse the array arr[]
    for(int i = 0; i < N; i++)
    {
         
        // Stores distance of the
        // point (X, Y) from i-th tower
        double dist = Math.sqrt((arr[i][0] - X) *
                                (arr[i][0] - X) +
                                (arr[i][1] - Y) *
                                (arr[i][1] - Y));
  
        // If dist lies within the
        // range of the i-th tower
        if (dist <= arr[i][2])
        {
            return true;
        }
    }
  
    // If the point (X, Y) does not lie
    // in the range of any of the towers
    return false;
}
  
// Driver Code
public static void main(String[] args)
{
    int arr[][] = { { 1, 1, 3 },
                    { 10, 10, 3 },
                    { 15, 15, 15 } };
    int X = 5, Y = 5;
  
    int N = arr.length;
  
    // If point (X, Y) lies in the
    // range of any of the towers
    if (checkPointRange(arr, X, Y, N))
    {
        System.out.print("True");
    }
     
    // Otherwise
    else
    {
        System.out.print("False");
    }
}
}
 
// This code is contributed by code_hunt

Python3

# Python3 program to implement
# the above approach
from math import sqrt
 
# Function to check if the point (X, Y)
# exists in the towers network-range or not
def checkPointRange(arr, X, Y, N):
     
    # Traverse the array arr[]
    for i in range(N):
         
        # Stores distance of the
        # point (X, Y) from i-th tower
        dist = sqrt((arr[i][0] - X) *
                    (arr[i][0] - X) +
                    (arr[i][1] - Y) *
                    (arr[i][1] - Y))
 
        # If dist lies within the
        # range of the i-th tower
        if (dist <= arr[i][2]):
            return True
 
    # If the point (X, Y) does not lie
    # in the range of any of the towers
    return False
 
# Driver Code
if __name__ == '__main__':
     
    arr = [ [ 1, 1, 3 ],
            [ 10, 10, 3 ],
            [ 15, 15, 15 ] ]
    X = 5
    Y = 5
 
    N =  len(arr)
 
    # If point (X, Y) lies in the
    # range of any of the towers
    if (checkPointRange(arr, X, Y, N)):
        print("True")
         
    # Otherwise
    else:
        print("False")
 
# This code is contributed by bgangwar59

C#

// C# program to implement
// the above approach 
using System;
   
class GFG{
   
// Function to check if the point (X, Y)
// exists in the towers network-range or not
static bool checkPointRange(int[,] arr, int X,
                            int Y, int N)
{
     
    // Traverse the array arr[]
    for(int i = 0; i < N; i++)
    {
         
        // Stores distance of the
        // point (X, Y) from i-th tower
        double dist = Math.Sqrt((arr[i, 0] - X) *
                                (arr[i, 0] - X) +
                                (arr[i, 1] - Y) *
                                (arr[i, 1] - Y));
   
        // If dist lies within the
        // range of the i-th tower
        if (dist <= arr[i, 2])
        {
            return true;
        }
    }
   
    // If the point (X, Y) does not lie
    // in the range of any of the towers
    return false;
}
   
// Driver Code
public static void Main()
{
    int[,] arr = { { 1, 1, 3 },
                   { 10, 10, 3 },
                   { 15, 15, 15 } };
                     
    int X = 5, Y = 5;
   
    int N = arr.Length;
   
    // If point (X, Y) lies in the
    // range of any of the towers
    if (checkPointRange(arr, X, Y, N))
    {
        Console.Write("True");
    }
      
    // Otherwise
    else
    {
        Console.Write("False");
    }
}
}
   
// This code is contributed by susmitakundugoaldanga

Javascript

 
// JavaScript program to implement
// the above approach
 
// Function to check if the polet (X, Y)
// exists in the towers network-range or not
function checkPointRange(arr, X, Y, N)
{
      
    // Traverse the array arr[]
    for(let i = 0; i < N; i++)
    {
          
        // Stores distance of the
        // polet (X, Y) from i-th tower
        let dist = Math.sqrt((arr[i][0] - X) *
                                (arr[i][0] - X) +
                                (arr[i][1] - Y) *
                                (arr[i][1] - Y));
   
        // If dist lies within the
        // range of the i-th tower
        if (dist <= arr[i][2])
        {
            return true;
        }
    }
   
    // If the point (X, Y) does not lie
    // in the range of any of the towers
    return false;
}
 
// Driver Code
 
    let arr = [[ 1, 1, 3 ],
               [ 10, 10, 3 ],
              [ 15, 15, 15 ]];
    let X = 5, Y = 5;
   
    let N = arr.length;
   
    // If point (X, Y) lies in the
    // range of any of the towers
    if (checkPointRange(arr, X, Y, N))
    {
        document.write("True");
    }
      
    // Otherwise
    else
    {
        document.write("False");
    }
           

输出：

True

时间复杂度： O(N)
辅助空间： O(1)

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