题解 | #手机键盘#

#include <bits/stdc++.h>
using namespace std;

int main() {
    string s;
    int k[26] = {1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 1, 2, 3, 4};
    while (cin >> s) {
        int count = 0 ;
        for (int i = 0 ; i < s.length() ; i++) {
            if (i != 0 and
                    s[i] - s[i - 1] == k[s[i] - 'a'] - k[s[i - 1] - 'a']) count = count + 2;
            count = count + k[s[i] - 'a'];
        }

        cout << count << endl;
    }
}

这个条件有点难思考：s[i] - s[i - 1] == k[s[i] - 'a'] - k[s[i - 1] - 'a'])

只想到了s[i] - s[i - 1] == 0