PAT A1027 Colors in Mars (20分)

PAT甲级：A1027 Colors in Mars (20分)

People in Mars represent the colors in their computers in a similar way as the Earth people. That is, a color is represented by a 6-digit number, where the first 2 digits are for Red, the middle 2 digits for Green, and the last 2 digits for Blue. The only difference is that they use radix 13 (0-9 and A-C) instead of 16. Now given a color in three decimal numbers (each between 0 and 168), you are supposed to output their Mars RGB values.

Input Specification:

Each input file contains one test case which occupies a line containing the three decimal color values.

Output Specification:

For each test case you should output the Mars RGB value in the following format: first output #, then followed by a 6-digit number where all the English characters must be upper-cased. If a single color is only 1-digit long, you must print a 0 to its left.

Sample Input:

15 43 71

Sample Output:

#123456

• 题意：把10进制转为13进制（0-9 和 A-C）。
• 分析：因为只需要转化两位数，所以不需要写成循环的形式，分别对十位和个位做转换即可。因为13进制包含字母，所以如果超过9，就减去10再加上’A’即可。

  #include <cstdio>
  char change(int x) { return x > 9 ? x - 10 + 'A' : x + '0'; }
  int main() {
      int n;
      printf("#");
      for (int i = 0; i < 3; i++) {
          scanf("%d", &n);
          printf("%c", change(n / 13));
          printf("%c", change(n % 13));
      }
      return 0;
  }