Given two positive integers h and w representing the height h and width w which forms a rectangle. Also, there are two arrays of integers horizontalCuts and verticalCuts where horizontalCuts[i] is the distance from the top of the rectangle to the ith horizontal cut and similarly, verticalCuts[j] is the distance from the left of the rectangle to the jth vertical cut. The task is to find the maximum area of the rectangle after you cut at each horizontal and vertical position provided in the arrays horizontalCuts and verticalCuts. Since the answer can be a huge number, return this modulo 10^9 + 7.
Examples :Â
max area = 6
Input: h = 6, w = 4, horizontalCuts = [2, 5], verticalCuts = [1, 3]
Output: 6
Explanation: The figure above represents the given rectangle. Red lines are the horizontal cuts and blue lines are vertical cuts. After the rectangle is cut, the green piece of rectangle has the maximum area.Input: h = 5, w = 4, horizontalCuts = [3, 1], verticalCuts = [1]
Output: 9
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Approach: The problem can be solved by observing that-
- The horizontalCuts if perpendicular to any VerticalCut, then all the vertical slices cross all the horizontalCuts.
- Next, the maximum area of the rectangle must be enclosed by at least one vertical and one horizontal cut.
From the above observation, it is clear that we need to find the maximum distance between two horizontal cuts and two vertical cuts respectively, and multiply them to find the area of the rectangle. Follow the steps below to solve the problem:
- Sort both horizontalCuts and verticalCuts lists.
- Initialize two variables, say MaxHorizontal and MaxVertical as horizontalCuts[0] and verticalCuts[0] respectively, as to consider the closest rectangles towards axis both horizontally and vertically which will store the maximum horizontal and vertical lengths of the rectangle respectively.
- Iterate in the range [1, horizontalCuts.size()-1] using the variable i and perform the following steps:
- Modify the value of MaxHorizontal as max(MaxHorizontal, horizontalCuts[i] – horizontalCuts[i-1]).
- Modify the value of MaxVertical as max(MaxVertical, verticalCuts[i] – verticalCuts[i-1]).
- Print MaxHorizontal*MaxVertical as the answer.
Below is the implementation of the above approach:
C++
// C++ Program for the above approach #include <bits/stdc++.h> using namespace std; const int mod = 1e9 + 7; Â
class Solution { public :     // Returns the maximum area of rectangle     // after Horizontal and Vertical Cuts     int maxArea( int h, int w, vector< int >& horizontalCuts,                 vector< int >& verticalCuts)     { Â
        // Sort the two arrays         sort(horizontalCuts.begin(), horizontalCuts.end());         sort(verticalCuts.begin(), verticalCuts.end()); Â
        // Insert the right bound h and w         // in their respective vectors         horizontalCuts.push_back(h);         verticalCuts.push_back(w);                    //Initialising both by first indexs,           //to consider first rectangle formed by           //respective horizontal and vertical cuts         int maxHorizontal = horizontalCuts[0];         int maxVertical = verticalCuts[0]; Â
        // Find the maximum Horizontal Length possible         for ( int i = 1; i < horizontalCuts.size(); i++) {             int diff                 = horizontalCuts[i] - horizontalCuts[i - 1];             maxHorizontal = max(maxHorizontal, diff);         } Â
        // Find the maximum vertical Length possible         for ( int i = 1; i < verticalCuts.size(); i++) {             int diff                 = verticalCuts[i] - verticalCuts[i - 1];             maxVertical = max(maxVertical, diff);         } Â
        // Return the maximum area of rectangle         return ( int )(( long )maxHorizontal * maxVertical                      % mod);     } }; Â
// Driver Code int main() {     // Class Call     Solution ob;        // Given Input     vector< int > hc = { 2, 5 }, vc = { 1, 3 };     int h = 6, v = 4;     // Function Call     cout << (ob.maxArea(6, 4, hc, vc));     return 0; } |
Java
// Java program for above approach import java.util.*; class GFG{     // Returns the maximum area of rectangle     // after Horizontal and Vertical Cuts     public static int maxArea( int h, int w, ArrayList<Integer> horizontalCuts,                     ArrayList<Integer> verticalCuts)     {         // Sort the two arrays         Collections.sort(horizontalCuts);         Collections.sort(verticalCuts); Â
        // Insert the right bound h and w         // in their respective vectors                      //if the set is empty, add 0 as default value           if (horizontalCuts.size() == 0 ){             horizontalCuts.add( 0 );           }         if (verticalCuts.size() == 0 ){               verticalCuts.add( 0 );         }         horizontalCuts.add(h);         verticalCuts.add(w); Â
        // int maxHorizontal = 0;         // int maxVertical = 0;                     int maxHorizontal = horizontalCuts.get( 0 );         int maxVertical = verticalCuts.get( 0 ); Â
        // Find the maximum Horizontal Length possible         for ( int i = 1 ; i < horizontalCuts.size(); i++) {             int diff                     = horizontalCuts.get(i) - horizontalCuts.get(i- 1 );             maxHorizontal = Math.max(maxHorizontal, diff);         } Â
        // Find the maximum vertical Length possible         for ( int i = 1 ; i < verticalCuts.size(); i++) {             int diff                     = verticalCuts.get(i) - verticalCuts.get(i - 1 );             maxVertical = Math.max(maxVertical, diff);         } Â
        // Return the maximum area of rectangle         return ( int )(( long )maxHorizontal * maxVertical);     }     // Driver Code     public static void main(String[] args)     {         // Given Input         ArrayList<Integer> hc = new ArrayList<>();         hc.add( 3 );                  ArrayList<Integer> vc = new ArrayList<>();         vc.add( 3 );         int h = 5 , v = 4 ;                // Function Call         System.out.println(maxArea( 6 , 4 , hc, vc));     } } Â
//This code is contributed by Piyush Anand. |
Python3
# python 3 Program for the above approach mod = 1000000007 Â
# Returns the maximum area of rectangle # after Horizontal and Vertical Cuts def maxArea(h, w, horizontalCuts, Â Â Â Â Â Â Â Â Â Â Â Â verticalCuts): Â
    # Sort the two arrays     horizontalCuts.sort()     verticalCuts.sort() Â
    # Insert the right bound h and w     # in their respective vectors     horizontalCuts.append(h)     verticalCuts.append(w) Â
    maxHorizontal = 0     maxVertical = 0 Â
    # Find the maximum Horizontal Length possible     for i in range ( 1 , len (horizontalCuts)): Â
        diff = horizontalCuts[i] - horizontalCuts[i - 1 ]         maxHorizontal = max (maxHorizontal, diff) Â
    # Find the maximum vertical Length possible     for i in range ( 1 ,                    len (verticalCuts)):         diff = verticalCuts[i] - verticalCuts[i - 1 ]         maxVertical = max (maxVertical, diff) Â
    # Return the maximum area of rectangle     return ( int )(maxHorizontal * maxVertical                  % mod) Â
Â
# Driver Code if __name__ = = "__main__" : Â
    # Given Input     hc = [ 2 , 5 ]     vc = [ 1 , 3 ]     h = 6     v = 4          # Function Call     print (maxArea( 6 , 4 , hc, vc)) Â
    # This code is contributed by ukasp. |
C#
// C# Program for the above approach using System; using System.Collections; using System.Collections.Generic; class GFG {     static int mod = 1000000007;          // Returns the maximum area of rectangle     // after Horizontal and Vertical Cuts     static int maxArea( int h, int w, List< int > horizontalCuts, List< int > verticalCuts)     {         // Sort the two arrays         horizontalCuts.Sort();         verticalCuts.Sort();               // Insert the right bound h and w         // in their respective vectors         horizontalCuts.Add(h);         verticalCuts.Add(w);               int maxHorizontal = 0;         int maxVertical = 0;               // Find the maximum Horizontal Length possible         for ( int i = 1; i < horizontalCuts.Count; i++)         {                   int diff = horizontalCuts[i] - horizontalCuts[i - 1];             maxHorizontal = Math.Max(maxHorizontal, diff);         }               // Find the maximum vertical Length possible         for ( int i = 1; i < verticalCuts.Count; i++)         {             int diff = verticalCuts[i] - verticalCuts[i - 1];             maxVertical = Math.Max(maxVertical, diff);         }               // Return the maximum area of rectangle         return ( int )(maxHorizontal * maxVertical % mod);     }        static void Main ()   {     // Given Input     List< int > hc = new List< int >( new int []{ 2, 5 });     List< int > vc = new List< int >( new int []{ 1, 3 });          // Function Call     Console.WriteLine(maxArea(6, 4, hc, vc));   } } Â
// This code is contributed by suresh07. |
Javascript
<script> Â Â Â Â Â Â Â Â // JavaScript program for the above approach Â
        const mod = 1e9 + 7; Â
        class Solution { Â
            // Returns the maximum area of rectangle             // after Horizontal and Vertical Cuts             maxArea(h, w, horizontalCuts, verticalCuts) { Â
                // Sort the two arrays                 horizontalCuts.sort( function (a, b) { return a - b; })                 verticalCuts.sort( function (a, b) { return a - b; }) Â
                // Insert the right bound h and w                 // in their respective vectors                 horizontalCuts.push(h);                 verticalCuts.push(w); Â
                let maxHorizontal = 0;                 let maxVertical = 0; Â
                // Find the maximum Horizontal Length possible                 for (let i = 1; i < horizontalCuts.length; i++) {                     let diff                         = horizontalCuts[i] - horizontalCuts[i - 1];                     maxHorizontal = Math.max(maxHorizontal, diff);                 } Â
                // Find the maximum vertical Length possible                 for (let i = 1; i < verticalCuts.length; i++) {                     let diff                         = verticalCuts[i] - verticalCuts[i - 1];                     maxVertical = Math.max(maxVertical, diff);                 } Â
                // Return the maximum area of rectangle                 return parseInt(maxHorizontal * maxVertical                     % mod);             }         } Â
        // Driver Code Â
        // Class Call         let ob = new Solution(); Â
        // Given Input         let hc = [2, 5], vc = [1, 3];         let h = 6, v = 4;         // Function Call         document.write(ob.maxArea(6, 4, hc, vc)); Â
    // This code is contributed by Potta Lokesh Â
    </script> |
6
Time Complexity: O(NlogN)
Auxiliary Space: O(1)
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