题解 | 手机键盘

#include <iostream>
using namespace std;
//构建判定分组的辅助数组和判定次数的辅助数组
int main() {
    string str;
    while (cin >> str) {
        int len = str.length();
        int cnt = 0;
        int pd[26];
        int cost[26];
        for (int i = 0; i < 26; i++) {
            if (i <= 14) {
                pd[i] = i / 3;
                cost[i] = i % 3 + 1;
            } else if (i > 14 and i <= 18) {
                pd[i] = 5;    //pqrs属于第5组
                cost[i] = i - 14;
            } else if (i > 18 and i <= 21) {
                pd[i] = 6;
                cost[i] = i - 18;
            }
            else
            {
                pd[i] = 7;
                cost[i] = i - 21;
            }

        }

        for (int i = 0; i < len - 1; i++) {
            int num1 = str[i] - 'a';
            int num2 = str[i + 1] - 'a';
            if (pd[num1] == pd[num2]) cnt += 2;
            cnt += cost[num1];
        }
        cnt += cost[str[len-1]-'a'];
        cout << cnt << endl;
    }
}
// 64 位输出请用 printf("%lld")