题解 | #密码截取#

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

int main() {
    string input;
    cin >> input;
    int max_length = 0;
    int left = 0, right = input.size() - 1;
    // 遍历，最右边的指针
    while (right) {
        for (left = 0; left < right; ++left) {
            if(input[left] == input[right]){
                int l = left, r = right;
                int length = 0;
                while(l < r){
                    if(input[l] == input[r]){
                        length += 2;
                    }else {
                        length = 0; break;
                    }
                    l++;
                    r--;
                }
                if(l == r) length += 1;
                max_length = max(max_length, length);
                if(length >= 1) break;
            }
        }
        right--;
    }
    cout << max_length << endl;
    return 0;
}
// 64 位输出请用 printf("%lld")

暴力 ，硬怼就是了！！！