Given lower left and upper right coordinates (x1, y1) and (x2, y2) of a square, the task is to count the number of integral coordinates that lies strictly inside the square.
Examples:
Input: x1 = 1, y1 = 1, x2 = 5, x3 = 5
Output: 9
Explanation:
Below is the square for the given coordinates:
Input: x1 = 1, y1 = 1, x2 = 4, x3 = 4
Output: 4
Approach: The difference between the x and y ordinates of the lower and upper right coordinates of the given squares gives the number integral points of x ordinates and y ordinates between opposite sides of square respectively. The total number of points that strictly lies inside the square is given by:
count = (x2 – x1 – 1) * (y2 – y1 – 1)
For Example:
In the above figure:
1. The total number of integral points inside base of the square is (x2 – x1 – 1).
2. The total number of integral points inside height of the square is (y2 – y1 – 1).
These (x2 – x1 – 1) integrals points parallel to the base of the square repeats (y2 – y1 – 1) number of times. Therefore the total number of integral points is given by (x2 – x1 – 1)*(y2 – y1 – 1).
Below is the implementation of the above approach:
C++
// C++ program for the above approach #include <bits/stdc++.h> using namespace std; // Function to calculate the integral // points inside a square void countIntgralPoints( int x1, int y1, int x2, int y2) { cout << (y2 - y1 - 1) * (x2 - x1 - 1); } // Driver Code int main() { int x1 = 1, y1 = 1; int x2 = 4, y2 = 4; countIntgralPoints(x1, y1, x2, y2); return 0; } |
Java
// Java program for the above approach class GFG { // Function to calculate the integral // points inside a square static void countIntgralPoints( int x1, int y1, int x2, int y2) { System.out.println((y2 - y1 - 1 ) * (x2 - x1 - 1 )); } // Driver Code public static void main(String args[]) { int x1 = 1 , y1 = 1 ; int x2 = 4 , y2 = 4 ; countIntgralPoints(x1, y1, x2, y2); } } // This code is contributed by rutvik_56 |
Python3
# Python3 program for the above approach # Function to calculate the integral # points inside a square def countIntgralPoints(x1, y1, x2, y2): print ((y2 - y1 - 1 ) * (x2 - x1 - 1 )) # Driver Code if __name__ = = '__main__' : x1 = 1 y1 = 1 x2 = 4 y2 = 4 countIntgralPoints(x1, y1, x2, y2) # This code is contributed by Samarth |
C#
// C# program for the above approach using System; class GFG{ // Function to calculate the integral // points inside a square static void countIntgralPoints( int x1, int y1, int x2, int y2) { Console.WriteLine((y2 - y1 - 1) * (x2 - x1 - 1)); } // Driver code static void Main() { int x1 = 1, y1 = 1; int x2 = 4, y2 = 4; countIntgralPoints(x1, y1, x2, y2); } } // This code is contributed by divyeshrabadiya07 |
Javascript
<script> // Javascript program for the above approach // Function to calculate the integral // points inside a square function countIntgralPoints(x1, y1, x2, y2) { document.write( (y2 - y1 - 1) * (x2 - x1 - 1)); } // Driver Code var x1 = 1, y1 = 1; var x2 = 4, y2 = 4; countIntgralPoints(x1, y1, x2, y2); </script> |
4
Time Complexity: O(1), as we are not using any loops.
Auxiliary Space: O(1), as we are not using any extra space.
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