Time Limit: 1000MS | Memory Limit: 10000K | |
Total Submissions: 35455 | Accepted: 17187 |
Description
A color reduction is a mapping from a set of discrete colors to a smaller one. The solution to this problem requires that you perform just such a mapping in a standard twenty-four bit RGB color space. The input consists of a target set of sixteen RGB color values, and a collection of arbitrary RGB colors to be mapped to their closest color in the target set. For our purposes, an RGB color is defined as an ordered triple (R,G,B) where each value of the triple is an integer from 0 to 255. The distance between two colors is defined as the Euclidean distance between two three-dimensional points. That is, given two colors (R1,G1,B1) and (R2,G2,B2), their distance D is given by the equation

Input
The input is a list of RGB colors, one color per line, specified as three integers from 0 to 255 delimited by a single space. The first sixteen colors form the target set of colors to which the remaining colors will be mapped. The input is terminated by a line containing three -1 values.
Output
For each color to be mapped, output the color and its nearest color from the target set.
If there are more than one color with the same smallest distance, please output the color given first in the color set.
If there are more than one color with the same smallest distance, please output the color given first in the color set.
Sample Input
0 0 0 255 255 255 0 0 1 1 1 1 128 0 0 0 128 0 128 128 0 0 0 128 126 168 9 35 86 34 133 41 193 128 0 128 0 128 128 128 128 128 255 0 0 0 1 0 0 0 0 255 255 255 253 254 255 77 79 134 81 218 0 -1 -1 -1
Sample Output
(0,0,0) maps to (0,0,0) (255,255,255) maps to (255,255,255) (253,254,255) maps to (255,255,255) (77,79,134) maps to (128,128,128) (81,218,0) maps to (126,168,9)
Source
Regionals 2001 >> North America - Greater NY
问题链接:POJ1046 ZOJ1076 UVALive2281 Color Me Less
问题描述:(略)
问题分析:
这个问题用枚举来解决,计算所有的距离再求个最值就可以了。开平方计算是不需要的,可以加快计算速度,但是需要注意最小值的初值设置。
程序说明:(略)
参考链接:(略)
题记:(略)
AC的C++语言程序如下:
/* POJ1046 ZOJ1076 UVALive2281 Color Me Less */
#include <iostream>
#include <stdio.h>
using namespace std;
const int N = 16;
struct Color {
int r, g, b;
} c[N];
int main()
{
for(int i = 0; i < N; i++)
scanf("%d%d%d", &c[i].r, &c[i].g, &c[i].b);
int r, g, b;
while(~scanf("%d%d%d", &r, &g, &b) && (r != -1 || g != -1 || b != -1)) {
int minc = 255 * 255 * 3, k = 0;
for(int i = 0; i < N; i++) {
int t = (c[i].r - r) * (c[i].r - r) + (c[i].g - g) * (c[i].g - g) + (c[i].b - b) * (c[i].b - b);
if(t < minc)
minc = t, k = i;
}
printf("(%d,%d,%d) maps to (%d,%d,%d)\n", r, g, b, c[k].r, c[k].g, c[k].b);
}
return 0;
}