1538 迎春舞会之数字舞蹈 题解

#include <iostream>

int main()
{
    /*
     * # Seven-segment Display
     *
     * The way how the program prints decimal numerics to the console works
     * similarly to seven-segment displays. The seven segments are arranged as
     * a rectangle of two vertical segments on each side with one horizontal
     * segment on the top, middle and bottom. The following diagram depicts the
     * layout of seven segments,
     *
     *   -
     *  | |
     *   -
     *  | |
     *   -
     *
     * # The Working of Seven-segment Display
     *
     * The number 8 is displayed when all the segments are visible, and if you
     * hide the horizontal segment on the middle, then we get the number 0. We
     * can form different combinations of seven segments for decimal numerics
     * from 0 through 9. We number each segment starting 0 from top to bottom,
     * left to right, as illustrated in the following diagram,
     *
     * Layout    Serial Number
     *  -         0
     * | |       1 2
     *  -         3
     * | |       4 5
     *  -         6
     *
     * # Mapping
     *
     * By using a serial number as a subscript of string and its corresponding
     * segment as the contents(i.e. a char), serial numbers provide a way to map
     * any layout of decimal numeric to a string. Here is the mappings of all
     * decimal numerics.
     *
     *      "-||-||-" // types of segments
     *      "0123456" // numbers of segments
     * 0 -> "-|| ||-"
     * 1 -> "  |  | "
     * 2 -> "- |-| -"
     * 3 -> "- |- |-"
     * 4 -> " ||- | "
     * 5 -> "-| - |-"
     * 6 -> "-| -||-"
     * 7 -> "- |  | "
     * 8 -> "-||-||-"
     * 9 -> "-||- |-"
     *
     */

    char indiction [10][8] = {"-|| ||-"
                             ,"  |  | "
                             ,"- |-| -"
                             ,"- |- |-"
                             ," ||- | "
                             ,"-| - |-"
                             ,"-| -||-"
                             ,"- |  | "
                             ,"-||-||-"
                             ,"-||- |-"
                             };

    int  k;
    char digits[1000];

    std::cin >> k >> digits;

    for (int seg = 0; seg < 7; seg++)
    {
        if (seg == 2 || seg == 5) continue; // Skip those vertical segments, we will deal with those in 1, 4 together

        if (seg % 3 == 0)   // Horizontal segments
        {
            for (int d = 0; digits[d]; d++)
            {
                std::cout << ' ';
                for (int i = 0; i < k; i++)
                {
                    std::cout << indiction[digits[d]-48][seg];
                }
                std::cout << "  ";
            }
            std::cout << '\n'; // EOL
        }
        else    // Vertical segments
        {
            for (int i = 0; i < k; i++)
            {
                for (int d = 0; digits[d]; d++)
                {
                    std::cout << indiction[digits[d]-48][seg];
                    for (int j = 0; j < k; j++)
                    {
                        std::cout << ' ';
                    }
                    std::cout << indiction[digits[d]-48][seg+1] << ' ';
                }
                std::cout << '\n'; // EOL
            }
        }
    }
    return 0;
}