题解 | 手机键盘

#include <iostream>
#include <string>
#include <vector>
using namespace std;

vector<int> keyTab={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};   

int main() {
    string str;
    while(cin>>str){
        int count = 0;
        for(int i=0;i<str.size()-1;i++){
            count+=keyTab[str[i]-'a'];
            if(keyTab[str[i]-'a']-keyTab[str[i+1]-'a']==
            str[i]-str[i+1]) count+=2;//此处的判断条件简直是神来之笔
        }
        count+=keyTab[str[str.size()-1]-'a'];
        cout<<count<<endl;
    }
    return 0;
    
}