hihocoder offer收割编程练习赛11 A hiho字符串

思路：

我用的尺取。

注意题目描述为恰好2个'h'，1个'i'，1个'o'。

实现：

 #include <iostream>
 #include <cstdio>
 #include <string>
 #include <algorithm>
 using namespace std;

 const int INF = 0x3f3f3f3f;

 int ch[], ci[], co[];

 bool check(int pos, int a, int b, int c)
 {
     return ch[pos] <= a -  && ci[pos] <= b -  && co[pos] <= c - ;
 }

 int main()
 {
     string s;
     cin >> s;
     int n = s.length();
     ch[] += (s[] == 'h');
     ci[] += (s[] == 'i');
     co[] += (s[] == 'o');
     int last = , min_len = INF;
     for (int i = ; i < n; i++)
     {
         ch[i] = ch[i - ] + (s[i] == 'h');
         ci[i] = ci[i - ] + (s[i] == 'i');
         co[i] = co[i - ] + (s[i] == 'o');
         if (ch[i] >=  && ci[i] >=  && co[i] >= )
         {
             while (last < i && check(last, ch[i], ci[i], co[i]))
             {
                 last++;
             }
             if (ch[i] - ch[last - ] ==  &&
                 ci[i] - ci[last - ] ==  &&
                 co[i] - co[last - ] == )
                 min_len = min(min_len, i - last + );
         }
     }
     if (min_len != INF)
         cout << min_len << endl;
     else
         cout << - << endl;
     return ;
 }