牛客 QQ3 编码
概述
https://www.nowcoder.com/practice/6fc8716ee33e4cc59d58d7e18712094e
递归
两点注意:
- return 那里要 + 1
 - 最终我们的结果会偏移一位,因此最终输出的时候 -1
 
#include <iostream>
#include <string>
using namespace std;
int s1 = 1;
int s2 = s1 + 25;
int s3 = s2 + 25 * 25;
int s4 = s3 + 25 * 25 * 25;
int step [4] = {s4, s3, s2, s1};
int helper(string& s, int i) {
    if (i == s.size()) return 0;
    int start = (s[i] - 'a') * step[i];
    return start + 1 + helper(s, i + 1);
}
int main() {
    string s;
    cin >> s;
    cout << helper(s, 0) - 1;
    return 0;
}
                
                Links: 牛客-qq03-编码