#include <bits/stdc++.h>
#define fi first
#define se second
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define bit(X,i) ((X>>i)&1)
#define fori(i,d,c) for(int i = d; i <= c; ++ i)
#define ford(i,d,c) for(int i = d; i >= c; -- i)
#define all(V) V.begin(), V.end()
#define RRH(V) V.resize(unique(all(V))-V.begin())
#define Task "palival"
using namespace std;
using ll = long long;
using ld = long double;
const int maxn = 1e5 + 5;
const int maxm = 1e6 + 5;
const int base = 101;
string s;
int n;
void read() {
cin >> s;
n = s.size();
s = " " + s;
}
namespace sub1{
int f[105][105];
int calc() {
ford(i,n,1) {
fori(j,i,n) {
if (j == i) f[i][j] = 1;
else {
if (s[i] == s[j]) {
if (i + 1 == j) f[i][j] = 1;
else f[i][j] = f[i+1][j-1];
}
else f[i][j] = 0;
}
}
}
int res = 0;
fori(i,1,n) fori(j,i,n) res += f[i][j];
return res;
}
void solve() {
int res = calc();
fori(i,1,n) {
char c = s[i];
fori(j,0,25) {
if (s[i] - 'a' == j) continue;
s[i] = char(j + 'a');
// if(calc() > res) {
// cout << i << ' ' << s[i] << '\n';
// }
res = max(res, calc());
}
s[i] = c;
}
cout << res;
}
}
ll Total_Result;
namespace tester {
int f[5005][5005];
int calc() {
ford(i,n,1) {
fori(j,i,n) {
if (j == i) f[i][j] = 1;
else {
if (s[i] == s[j]) {
if (i + 1 == j) f[i][j] = 1;
else f[i][j] = f[i+1][j-1];
}
else f[i][j] = 0;
}
}
}
int res = 0;
fori(i,1,n) fori(j,i,n) res += f[i][j];
return res;
}
void solve() {
int cs = -1, sum = 0;
fori(i,2,n-1) {
if (s[i-1] == s[i+1]) {
int j = i-1;
while(j - 1 >= 1 && s[j-1] == s[j]) j --;
int j1 = i+1;
while(j1 + 1 <= n && s[j1 + 1] == s[j1]) j1 ++;
if (j1 - j + 1 > sum) {
cs = i;
sum = j1 - j + 1;
}
}
}
int res = calc();
if (1){
int sum1 = 0;
int cs1 = 0, cs2 = n + 1;
for(int i = 1; i <= n;) {
int j1 = i;
while(j1 + 1 <= n && s[j1 + 1] == s[i]) j1 ++;
if (sum1 < j1 - i + 1) {
sum1 = j1 - i + 1;
cs1 = i - 1;
cs2 = j1 + 1;
}
i = j1 + 1;
}
if (cs1 >= 1) {
char c = s[cs1];
s[cs1] = s[cs1 + 1];
res = max(res, calc());
s[cs1] = c;
}
if (cs2 <= n) {
char c = s[cs2];
s[cs2] = s[cs2-1];
res = max(res, calc());
s[cs2] = c;
}
Total_Result = max(Total_Result, 1ll * res);
}
if (cs != -1){
s[cs] = s[cs-1];
res = max(res, calc());
Total_Result = max(Total_Result, 1ll * res);
}
}
}
namespace sub2 {
int f[5005][5005];
int calc() {
ford(i,n,1) {
fori(j,i,n) {
if (j == i) f[i][j] = 1;
else {
if (s[i] == s[j]) {
if (i + 1 == j) f[i][j] = 1;
else f[i][j] = f[i+1][j-1];
}
else f[i][j] = 0;
}
}
}
int res = 0;
fori(i,1,n) fori(j,i,n) res += f[i][j];
return res;
}
int dif(int i, int j) {
int cnt = 0;
while(i <= j) {
if (s[i] != s[j]) {
cnt ++;
}
i ++; j --;
}
return cnt;
}
void solve() {
int sum = 0, cs1 = 0, cs2 = 0;
fori(i,1,n) fori(j,i,n){
if (dif(i,j) <= 1) {
if (sum < j - i + 1) {
sum = j - i + 1;
cs1 = i; cs2 = j;
}
}
}
int res = calc();
while(cs1 <= cs2) {
if (s[cs1] != s[cs2]) {
char c = s[cs1];
s[cs1] = s[cs2];
res = max(res, calc());
s[cs1] = c;
s[cs2] = s[cs1];
res = max(res, calc());
break;
}
cs1 ++;
cs2 --;
}
cout << res;
}
}
void solve() {
Total_Result = n;
// if (n <= 100) sub1::solve();
// else {
// tester::solve();
// cout << Total_Result;
// }
sub2::solve();
}
int main () {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
if (fopen(Task".inp", "r")) {
freopen(Task".inp", "r", stdin);
freopen(Task".out", "w", stdout);
}
read();
solve();
cerr << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";
return 0;
}
Compilation message
palinilap.cpp: In function 'int main()':
palinilap.cpp:210:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
210 | freopen(Task".inp", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
palinilap.cpp:211:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
211 | freopen(Task".out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
2392 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1004 ms |
344 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1059 ms |
604 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
