/*
Author: Cadocx
Codeforces: https://codeforces.com/profile/Kadoc
VNOJ: oj.vnoi.info/user/Cadoc
*/
#include <bits/stdc++.h>
using namespace std;
// input/output
#define fastIO ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define el cout << '\n'
#define execute cerr << "Time elapsed: " << (1.0 * clock() / CLOCKS_PER_SEC) << "s"
// #pragma GCC optimize("O2", "unroll-loops", "Ofast")
// #pragma GCC target("avx,avx2,fma")
//data type
#define int128 __uint128_t
#define ll long long
#define ull unsigned long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define piv pair<int, vector<int>>
#define vi vector<int>
#define vl vector<ll>
#define vc vector<char>
//STL
#define sz(x) (int)(x).size()
#define for1(i,l,r) for(auto i = l; i <= r; i++)
#define for2(i,r,l) for(auto i = r; i >= l; i--)
#define forin(i,a) for(auto i : a)
#define pb push_back
#define eb emplace_back
#define pf push_front
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second
//bitmask
#define bitcnt(n) __builtin_popcount(n)
#define mask(i) (1 << (i))
#define bit(n, i) (((n) >> (i)) & 1)
#define set_on(n, i) ((n) | mask(i))
#define set_off(n, i) ((n) & ~mask(i))
//constant
#define N 1000005
#define MOD 1000230007
#define INF 0x3f3f3f3f
#define LINF 0x3f3f3f3f3f3f3f3f
#define base 31
#define Kadoc 0
int n;
vector<int> pos[32];
ll ans = 0, Min[N];
void calc(int x, int y){
if(x == y || !pos[x].size() || !pos[y].size()) return;
vector<int> a; a.pb(0);
for(int i=0, j=0; i<sz(pos[x]) || j<sz(pos[y]);){
if(j == sz(pos[y]) || (i < sz(pos[x]) && pos[x][i] <= pos[y][j])){
a.pb(1);
i++;
}
else{
a.pb(-1);
j++;
}
}
int last = -1, m = sz(a)-1; Min[0] = 0;
ll s = 0;
for(int i=1; i<=m; ++i){
s += a[i];
Min[i] = min(Min[i-1], s);
if(a[i] == -1) last = i;
if(last != -1) ans = max(ans, s - Min[last-1]);
}
}
void solve(){
cin >> n;
for(int i=1; i<=n; ++i){
char x; cin >> x;
pos[x-'a'+1].pb(i);
}
for(int i=1; i<=26; ++i) for(int j=1; j<=26; ++j) calc(i, j);
cout << ans;
}
int main(){
#define NAME "TASK"
if(fopen(NAME".inp", "r")){
freopen(NAME".inp", "r", stdin);
freopen(NAME".out", "w", stdout);
}
fastIO;
if(Kadoc){
int tc; cin >> tc;
while(tc--){
solve();
}
} else solve();
}
Compilation message
roz.cpp: In function 'int main()':
roz.cpp:95:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
95 | freopen(NAME".inp", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
roz.cpp:96:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
96 | freopen(NAME".out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
56 ms |
1116 KB |
Output is correct |
2 |
Correct |
1 ms |
596 KB |
Output is correct |
3 |
Correct |
3 ms |
616 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
561 ms |
7452 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
323 ms |
6376 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
552 ms |
7492 KB |
Output is correct |
2 |
Correct |
444 ms |
5816 KB |
Output is correct |
3 |
Correct |
146 ms |
7636 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
570 ms |
7484 KB |
Output is correct |
2 |
Correct |
79 ms |
17328 KB |
Output is correct |
3 |
Correct |
112 ms |
9084 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
554 ms |
7388 KB |
Output is correct |
2 |
Correct |
45 ms |
20996 KB |
Output is correct |
3 |
Correct |
184 ms |
8332 KB |
Output is correct |