题解 | 小红的双生串

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

unordered_map<char,int> mp1,mp2;
int ma1 = -1,ma2 = -1;

int main() {
    string str;
    cin>>str;
    int len = str.size()>>1;

    for(int i = 0;i<len;i++){
        ma1 = max(ma1,++mp1[str[i]]);
    }
    for(int i = len;i<str.size();i++){
        ma2 = max(ma2,++mp2[str[i]]);
    }

    cout<<2*len-ma1-ma2;

    return 0;
}
// 64 位输出请用 printf("%lld")