// Author : Nguyen Anh Tuan - THPT Chuyen Bac Giang - Train VOI 2023/2024
#include<bits/stdc++.h>
#define file(NAME) {freopen(NAME".inp", "r", stdin); freopen(NAME".out", "w", stdout);}
#define foru(i, a, b) for(int i=(a);i<=(b);i++)
#define ford(i, a, b) for(int i=(a);i>=(b);i--)
#define rep(i, n) for(int i=(1);i<=(n);i++)
#define fi first
#define se second
#define mp make_pair
#define SZ(v) ((int)((v).size()))
#define all(v) v.begin(),v.end()
#define RR(X) X.resize(unique(all(X)) - begin(X))
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
namespace IO
{
#define getchar() (ipos==iend and (iend=(ipos=_ibuf)+fread(_ibuf,1,__bufsize,stdin),ipos==iend)?EOF:*ipos++)
#define putchar(ch) (opos==oend?fwrite(_obuf,1,__bufsize,stdout),opos=_obuf:0,*opos++=(ch))
#define __bufsize (1<<20)
char _ibuf[__bufsize],_obuf[__bufsize],_stk[20];
char *ipos=_ibuf,*iend=_ibuf,*opos=_obuf,*oend = _obuf+__bufsize,*stkpos = _stk;
struct END{~END(){fwrite(_obuf,1,opos-_obuf,stdout);}}__;
inline void read(int &x)
{
register ll f=0,ch;
for(;!isdigit(ch);ch=getchar())if(ch=='-')f=1;
for(x=0;isdigit(ch);ch=getchar())x=(x<<3ll)+(x<<1ll)+(ch^48);
x=f?-x:x;
}
inline void write(int x)
{
if(x<0)putchar('-'),x=-x;
while(*++stkpos=x%10^48,x/=10,x);
while(stkpos!=_stk)putchar(*stkpos--);
}
inline void lread(ll&x)
{
register ll f=0,ch;
for(;!isdigit(ch);ch=getchar())if(ch=='-')f=1;
for(x=0;isdigit(ch);ch=getchar())x=(x<<3ll)+(x<<1ll)+(ch^48);
x=f?-x:x;
}
inline void lwrite(ll x)
{
if(x<0)putchar('-'),x=-x;
while(*++stkpos=x%10^48,x/=10,x);
while(stkpos!=_stk)putchar(*stkpos--);
}
};
void maximum(ll &a, ll b) {if(b > a) a = b;}
void minimum(ll &a, ll b) {if(b < a) a = b;}
bool bit(int x, int i) {return (x >> i) & 1;}
//-----------------------------------------------------------------------------------
// END OF TEMPLATE
//-----------------------------------------------------------------------------------
// Nguyen Anh Tuan - AnhTuan_BG
// PRAY FOR VOI 2023
//-----------------------------------------------------------------------------------
string s;
int n;
namespace sub1
{
const int maxn = 5005;
bool f[maxn][maxn];
ll ans = 0;
ll Calc()
{
//cout << s << "\n";
int tmp = 0;
foru(i, 1, n) foru(j, 1, n) f[i][j] = 0;
ford(i, n, 1)
{
f[i][i] = 1;
if(s[i] == s[i + 1]) f[i][i + 1] = 1;
foru(j, i + 2, n)
{
if(s[i] == s[j]) f[i][j] = f[i + 1][j - 1];
}
}
foru(i, 1, n) foru(j, i, n) tmp = tmp + f[i][j];
//cout << tmp << "\n";
return tmp;
}
void solve()
{
ans = Calc();
foru(i, 1, n)
{
char x = s[i];
foru(j, 0, 25)
{
if(j == x - 'a') continue;
s[i] = char('a' + j);
ans = max(ans, Calc());
}
s[i] = x;
}
cout << ans;
}
}
namespace sub2
{
const int maxn = 5005;
ll dp[maxn][30];
bool f[maxn][maxn];
ll maxx[maxn];
void solve()
{
ford(i, n, 1)
{
f[i][i] = 1;
if(s[i] == s[i + 1]) f[i][i + 1] = 1;
foru(j, i + 2, n)
{
if(s[i] == s[j]) f[i][j] = f[i + 1][j - 1];
}
}
foru(i, 0, 25) dp[1][i] = 1;
maxx[1] = 1;
foru(i, 2, n)
{
foru(j, 0, 25)
{
dp[i][j] = 1;
if(j == s[i] - 'a') continue;
foru(k, 1, i - 1)
{
if((k == i - 1 || f[k + 1][i - 1]) && (j == s[k] - 'a'))
{
//dp[i][j] = dp[i][j] + dp[k][s[k] - 'a'];
dp[i][j]++;
}
}
maxx[i] = max(maxx[i], dp[i][j]);
}
//ll sum = 0;
foru(k, 1, i - 1)
{
if(k == i - 1 || f[k + 1][i - 1])
{
//sum = sum + dp[k][s[k] - 'a'];
dp[i][s[i] - 'a'] = max(dp[k][s[k] - 'a'] + 1, dp[i][s[i] - 'a']);
}
}
// foru(k, 1, i - 1)
// {
// if(k == i - 1 || f[k + 1][i - 1])
// dp[i][s[i] - 'a'] = max(dp[i][s[i] - 'a'], sum - dp[k][s[k] - 'a'] + maxx[k]);
// }
maxx[i] = max(maxx[i], dp[i][s[i] - 'a']);
}
foru(i, 1, n)
{
foru(j, 0, 25) cout << dp[i][j] << " ";
cout << "\n";
}
cout << maxx[n];
}
}
int main()
{
ios_base :: sync_with_stdio(0);
cin.tie(0); cout.tie(0);
//file("");
cin >> s;
n = s.size();
s = " " + s;
sub1 :: solve();
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
12 ms |
4440 KB |
Output is correct |
2 |
Correct |
18 ms |
4444 KB |
Output is correct |
3 |
Correct |
21 ms |
4444 KB |
Output is correct |
4 |
Correct |
23 ms |
4444 KB |
Output is correct |
5 |
Correct |
21 ms |
4544 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
1058 ms |
26968 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
33 ms |
56652 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |