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NOVEMBER 2025 / ADVANCED / QUESTION 7

Question 7

Archived question

Try the question in your own editor, then check your output below.

THE QUESTION

Text from the official booklet. Refer to the PDF for original mathematical notation, formatting, and linked input files. Printed samples and inputs are reproduced as published.

At WonderLand Theme Park, there are N attractions (3 ≤ N ≤ 50, 000), each located
at a distinct point on a 2D map.
The map is a coordinate grid. Each attraction is at a point ( x, y), where x and y are
positive integers between 1 and 1 , 000, 000, 000.
The park management wants to build fences around the attractions to mark safety zones.
Single Enclosure: If they build one rectangular fence:
• The fence must have sides parallel to the x- and y-axes.
• It must contain every attraction (attractions on the boundary are allowed).
• Among all such rectangles, they will choose the smallest possible one (with mini-
mum area) that contains all attractions.
Two Enclosures: However, the park wants to save money on maintenance by reducing
the total fenced area. They consider using two separate rectangular enclosures instead
of one:
• Each enclosure must also have sides parallel to the axes.
• Together, the two enclosures must still contain all attractions (every attraction
must lie inside at least one of the two rectangles; being on the boundary is allowed).
• The two rectangles are not allowed to overlap, not even at the boundary (they
must be completely disjoint).
• Rectangles with zero area are allowed (for example, if width = 0 or height = 0).
Goal: Compute how much total area the park can save by using two enclosures instead
of one.
Input Format:
• First line: N – the number of attractions.
• Next N lines: Each contains two integers x y, the coordinates of an attraction.
All attraction positions are distinct, and 1 ≤ x, y≤ 1, 000, 000, 000.
Output Format: Output a single integer: The maximum area saved by using two
enclosures instead of one.
Sample Input:
6
4 2
8 10
1 1
9 12
14 7
2 3
Sample Output:
107
Question Input:
100
10 12
14 18
18 20
22 25
26 30
30 35
34 40
38 45
42 50
46 55
50 60
54 65
58 70
62 75
66 80
70 85
74 90
78 95
82 100
86 105
12 14
16 22
20 28
24 34
28 42
32 48
36 52
40 58
44 63
48 68
52 73
56 78
60 83
64 88
68 92
72 96
76 102
80 108
84 114
88 120
15 130
20 135
25 140
30 145
35 150
40 155
45 160
50 165
55 170
60 175
65 180
70 185
75 190
80 195
85 200
18 150
22 144
26 138
30 132
34 126
38 120
42 116
46 112
50 108
54 104
58 100
62 96
66 92
70 88
74 84
78 80
82 76
86 72
90 68
94 64
98 60
102 56
106 52
110 48
114 44
118 40
122 36
126 32
130 28
134 24
138 20
142 16
146 12
150 18
154 24
158 30
162 36
166 42
170 48
174 54
178 60
182 66
186 72
190 78
194 84
198 90
199 95
200 100

CHECK YOUR ANSWER

Try your answer.

The final input declares 100 points but supplies 103. This check uses all 103 supplied points.

Run your program in your own editor, then paste its output below. This checks the stated output; it does not assess your full program. Practice attempts do not affect competition scores.

Use the question input above. Enter only the output.

Reveal worked answer

Your output

11846

Try every strictly separating horizontal and vertical cut. For each, sum the two minimum bounding-box areas. Subtract the minimum sum from the one-box area.

Source: Girls in Code SEA 2025 Fall Competition, 29 November 2025. Booklet created by Emily Xu and the GIC question authors. Shared for non-commercial educational use with attribution, as permitted in the booklet.