Check if given point lies in range of any of the given towers

Namachila November 19, 2025

0 1 5 minutes read

Given a 2D array arr[][] consisting of N rows of the form {X_i, Y_i, R_i} such that (X_i, Y_i) represents the position of a tower and R_i represents the network range of that tower. Given two integers X and Y, the task is to check if the point (X, Y) lies in the network range of the towers or not.

Examples:

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

Approach: Follow the steps given below to solve the problem:

Traverse the array and for each row ( tower ) traversed,
- Check if the value of sqrt((arr[i][0] – x)² + (arr[i][1] – Y)²) is greater than arr[i][2] or not.
- If found to be true, then print True.
- Otherwise, print False.

Below is the implementation of the above approach.

C++

// C++ program to implement
// the above approach
 
#include <bits/stdc++.h>
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

<script>
 
// JavaScript program to implement
// the above approach
 
// Function to check if the point (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
        // point (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");
    }
           
</script>

Output

True

Time Complexity: O(N * log(N)), in-built sqrt function has log(N) time complexity.
Auxiliary Space: O(1)

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