結果
| 問題 | No.588 空白と回文 | 
| コンテスト | |
| ユーザー |  | 
| 提出日時 | 2017-11-03 22:48:55 | 
| 言語 | C++17(gcc12) (gcc 12.3.0 + boost 1.87.0) | 
| 結果 | 
                                AC
                                 
                             | 
| 実行時間 | 4 ms / 2,000 ms | 
| コード長 | 3,842 bytes | 
| コンパイル時間 | 12,739 ms | 
| コンパイル使用メモリ | 272,436 KB | 
| 最終ジャッジ日時 | 2025-01-05 03:43:02 | 
| ジャッジサーバーID (参考情報) | judge4 / judge2 | 
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| ファイルパターン | 結果 | 
|---|---|
| other | AC * 25 | 
ソースコード
#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
#include "bits/stdc++.h" // define macro "/D__MAI"
using namespace std;
typedef long long int ll;
#define xprintf(fmt,...) fprintf(stderr,fmt,__VA_ARGS__)
#define debugv(v) {printf("L%d %s > ",__LINE__,#v);for(auto e:v){cout<<e<<" ";}cout<<endl;}
#define debuga(m,w) {printf("L%d %s > ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout<<endl;}
#define debugaa(m,h,w) {printf("L%d %s >\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[y][x]<<" ";}cout<<endl;}}
#define ALL(v) (v).begin(),(v).end()
#define repeat(cnt,l) for(auto cnt=0ll;(cnt)<(l);++(cnt))
#define iterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);++(cnt))
#define MD 1000000007ll
#define PI 3.1415926535897932384626433832795
#define EPS 1e-12
template<typename T1, typename T2> ostream& operator <<(ostream &o, const pair<T1, T2> p) { o << "(" << p.first << ":" << p.second << ")"; return o; }
template<typename iterator> inline size_t argmin(iterator begin, iterator end) { return distance(begin, min_element(begin, end)); }
template<typename iterator> inline size_t argmax(iterator begin, iterator end) { return distance(begin, max_element(begin, end)); }
template<typename T> T& maxset(T& to, const T& val) { return to = max(to, val); }
template<typename T> T& minset(T& to, const T& val) { return to = min(to, val); }
void bye(string s, int code = 0) { cout << s << endl; exit(0); }
mt19937_64 randdev(8901016);
inline ll rand_range(ll l, ll h) {
    return uniform_int_distribution<ll>(l, h)(randdev);
}
#ifdef __MAI
#define getchar_unlocked getchar
#define putchar_unlocked putchar
#endif
#ifdef __VSCC
#define getchar_unlocked _getchar_nolock
#define putchar_unlocked _putchar_nolock
#endif
namespace {
#define isvisiblechar(c) (0x21<=(c)&&(c)<=0x7E)
    class MaiScanner {
    public:
        template<typename T> void input_integer(T& var) {
            var = 0;
            T sign = 1;
            int cc = getchar_unlocked();
            for (; cc<'0' || '9'<cc; cc = getchar_unlocked())
                if (cc == '-') sign = -1;
            for (; '0' <= cc&&cc <= '9'; cc = getchar_unlocked())
                var = (var << 3) + (var << 1) + cc - '0';
            var = var*sign;
        }
        inline int c() { return getchar_unlocked(); }
        inline MaiScanner& operator>>(int& var) {
            input_integer<int>(var);
            return *this;
        }
        inline MaiScanner& operator>>(long long& var) {
            input_integer<long long>(var);
            return *this;
        }
        inline MaiScanner& operator>>(string& var) {
            int cc = getchar_unlocked();
            for (; !isvisiblechar(cc); cc = getchar_unlocked());
            for (; isvisiblechar(cc); cc = getchar_unlocked())
                var.push_back(cc);
            return *this;
        }
        template<typename IT> void in(IT begin, IT end) {
            for (auto it = begin; it != end; ++it) *this >> *it;
        }
    };
}
MaiScanner scanner;
// オンライン回文判定
bool iskaibun(const string& str) {
    int left = 0;
    int right = str.size() - 1;
    while (left < right) {
        if (str[left] != str[right]) return false;
        ++left; --right;
    }
    return true;
}
// 
ll m, n, kei;
int main() {
    string str;
    scanner >> str;
    n = (int)str.size();
    int best = 1;
    repeat(center, n) {
        int cnt = 1;
        for (int i = 1; 0 <= center - i && center + i < n; ++i)
            cnt += (str[center - i] == str[center + i]) * 2;
        maxset(best, cnt);
    }
    repeat(center, n-1) {
        int cnt = 0;
        for (int i = 0; 0 <= center - i && center + i+1 < n; ++i)
            cnt += (str[center - i] == str[center + i+1]) * 2;
        maxset(best, cnt);
    }
    cout << best << endl;
    return 0;
}
            
            
            
        