Closest Web Color Name

Interview

Time limit2sMemory limit256 MB

Summary

The program maps each RGB triple to the closest of 16 named HTML colors by Euclidean distance, breaking ties by table order.

Level: Easy2 of 10
Topics: Brute force, Math
Solved: No attempts yet

Problem

Web colors are the colors used to display web pages. A single color is given either as an RGB triple or as the English name of that color. A color is set by the intensity of its red, green and blue components, and each component takes eight bits, so one web color needs 24 bits and there are 16,777,216 web colors in total. The HTML 4 specification names only the 16 colors in the table below.

Mapping an arbitrary color to one of the named HTML colors is a common task. This problem asks for that mapping in RGB space.

The color closest to a given color is the one at the smallest Euclidean distance. If the color to map is $(r, g, b)$ and the 16 HTML colors are $(R_1, G_1, B_1)$ through $(R_{16}, G_{16}, B_{16})$ , the closest color minimizes

$d = \sqrt{(R_i - r)^2 + (G_i - g)^2 + (B_i - b)^2}$

where $i$ is an integer from 1 to 16.

#	Name	Red	Green	Blue
1	White	255	255	255
2	Silver	192	192	192
3	Gray	128	128	128
4	Black	0	0	0
5	Red	255	0	0
6	Maroon	128	0	0
7	Yellow	255	255	0
8	Olive	128	128	0
9	Lime	0	255	0
10	Green	0	128	0
11	Aqua	0	255	255
12	Teal	0	128	128
13	Blue	0	0	255
14	Navy	0	0	128
15	Fuchsia	255	0	255
16	Purple	128	0	128

Input

The input holds several test cases. Each test case is one line with three integers $r$ , $g$ , $b$ ( $0 \le r, g, b \le 255$ ), the red, green and blue intensities of a color.

The last line of the input is -1 -1 -1 and is not processed.

Output

For each test case, print on its own line the name of the HTML color closest to the given color, spelled as in the table. If two or more colors are equally close, print the name of the one with the smaller number in the table.

Examples3

Example 1

Input

120 120 10
111 112 113
5 135 8
-1 -1 -1

Expected output

Olive
Gray
Green

Example 2

Input

255 255 255
192 192 192
128 128 128
0 0 0
255 0 0
128 0 0
255 255 0
128 128 0
-1 -1 -1

Expected output

White
Silver
Gray
Black
Red
Maroon
Yellow
Olive

Example 3

Input

Expected output

Lime
Green
Aqua
Teal
Blue
Navy
Fuchsia
Purple