ZeroJudge E641: Soundex

同題：UVa 10260 – Soundex

Soundex encoding groups words that sound similar based on their spelling.
For example: "can" and "khawn," "con" and "gone."
Soundex encoding converts each word into a sequence of numbers, where each number represents a letter.

Below is the Soundex encoding table:

• 1：B、F、P、V
• 2：C、G、J、K、Q、S、X、Z
• 3：D、T
• 4：L
• 5：M、N
• 6：R

The letters "A, E, I, O, U, H, W, Y" are not represented in the Soundex encoding.
If letters with the same encoding appear adjacent to each other, they are represented by a single digit in the Soundex encoding.
Words with the same Soundex encoding are considered the same word.

Sample Inputs/Outputs

Thought Process

Use a map to record the Soundex code corresponding to each character, and store them using character keys. This approach allows accumulating the answer using strings. Characters not present in the Soundex code do not need to be explicitly declared; they will default to 0 when the map is initialized.

對收到字串的每一個字元做判斷，如果目前字元的 Soundex Code 不為 0，則要判斷這個字元是否為第一個 Soundex Code，可以在迴圈外面宣告一個布林值來確認，如果為第一個 Soundex Code，則將在迴圈外面宣告的字串 ans 變數 (預設為 “”) += Map[目前字元]，並且還要在迴圈的外面宣告一個字元 last 代表上一個 Soundex Code，將 last 設為 Map[目前字元]。如果不是第一個 Soundex Code 則要判斷目前的 Soundex Code 是否與 last 一致，如果不一致的話就要將 ans += Map[目前字元]，並且要將 last 設為新的 Map[目前字元]。

如果 Soundex Code 為 0，代表之後的要重新做判斷，所以要將 last 設為 ‘0’。

Sample Code－ZeroJudge E641: Soundex

#include <iostream>
#include <map>
using namespace std;

int main() {
    cin.sync_with_stdio(0);
    cin.tie(0);
    map<char, char>MAP;
    MAP['B'] = '1';
    MAP['F'] = '1';
    MAP['P'] = '1';
    MAP['V'] = '1';
    MAP['C'] = '2';
    MAP['G'] = '2';
    MAP['J'] = '2';
    MAP['K'] = '2';
    MAP['Q'] = '2';
    MAP['S'] = '2';
    MAP['X'] = '2';
    MAP['Z'] = '2';
    MAP['D'] = '3';
    MAP['T'] = '3';
    MAP['L'] = '4';
    MAP['M'] = '5';
    MAP['N'] = '5';
    MAP['R'] = '6';
    string str;
    while (cin >> str) {
        bool first = true;
        string ans = "";
        char last;
        for (int i = 0; i<str.length(); i++) {
            const char ch = str[i];
            if (MAP[ch] != 0) {
                if (first) {
                    first = false;
                    ans += MAP[ch];
                    last = MAP[ch];
                }
                else {
                    if (MAP[ch] != last) {
                        ans += MAP[ch];
                        last = MAP[ch];
                    }
                }
            }
            else last = '0';
        }
        cout << ans << "\n";
    }
}

//ZeroJudge E641
//Dr. SeanXD