AOJ 0176 - What Color?

再びVimで書いた．
フォントサイズが小さい
dkが同じ数値の場合に対応するために逆順に調べました．

#include <iostream>
#include <cmath>
int hextodec(char h){
  int res;
  if(h >= '0' && h <= '9')
    res = h - '0';
  else
    res = h - 'a' + 10;
  return res;
}

int main(){
  int color[8][3] = {{0, 0, 0}, {0, 0, 256}, {0, 256, 0},
                     {0, 256, 256}, {256, 0, 0}, {256, 0, 256},
                     {256, 256, 0}, {256, 256, 256}};
  std::string name[8] = {"black", "blue", "lime",
                         "aqua", "red", "fuchsia",
                         "yellow", "white"};

  std::string c;
  while(std::cin >> c, c.compare("0")){
    int r = hextodec(c[1]) * 16 + hextodec(c[2]),
        g = hextodec(c[3]) * 16 + hextodec(c[4]),
        b = hextodec(c[5]) * 16 + hextodec(c[6]);
    int min_v = 1000000, min_c;
    for(int i=7;i>=0;i--){
      if(color[i][0] == r && color[i][1] == g && color[i][2] == b){
        min_c = i; break;
      }
      int t = pow(r-color[i][0], 2) + pow(g-color[i][1], 2) +
              pow(b-color[i][2], 2);
      if(min_v > t)min_v = t, min_c = i;
    }
    std::cout << name[min_c] << std::endl;
  }
}