#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define fi first
#define se second
#define vi vector<int>
#define vll vector<long long>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());
inline int rand(int l,int r){return uniform_int_distribution<int>(l, r)(rng);}
inline ll rand(ll l,ll r){return uniform_int_distribution<ll>(l, r)(rng64);}
#ifdef DEBUG
auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";}
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X)
#else
#define debug(...){}
#endif
struct custom_hash {
static uint64_t splitmix64(uint64_t x) {
x += 0x9e3779b97f4a7c15;
x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
return x ^ (x >> 31);
}
size_t operator()(uint64_t x) const {
static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
return splitmix64(x + FIXED_RANDOM);
}
};
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
string s;
cin >> s;
int n = sz(s);
set<char> xd;
for(auto ele : s){
xd.insert(ele);
}
int g = sz(xd);
vector<char> vec;
for(auto ele : xd){
vec.pb(ele);
}
if(g == 1){
ld ans = (ld)(n / 2) * (n / 2 - 1) / 4 + (ld)(n - n / 2) * (n - n / 2 - 1) / 4;
cout << fixed << setprecision(5) << ans << '\n';
return 0;
}
vi p;
for(int i = 0; i < g; i++){
p.pb(i);
}
ld ans = 1e18;
do{
//cout << "----\n";
ld akt = 0;
int used = 0;
vi ok(n, 0);
for(int i = 0; i < g; i++){
pii cnt = {0, 0};
int onL = 0;
for(int j = 0; j < n; j++){
if(s[j]== vec[p[i]]){
if(onL <= used - onL){
cnt.fi++;
akt += onL;
}else{
akt += (used - onL);
cnt.se++;
}
}else if(ok[j]){
onL++;
}
}
for(int j = 0; j < n; j++){
if(s[j]== vec[p[i]]){
used++;
ok[j] = 1;
}
}
if(used == cnt.fi + cnt.se){
int ile = cnt.fi + cnt.se;
akt += ((ld)(ile / 2) * (ile / 2 - 1) / 4);
akt += ((ld)(ile - ile / 2) * (ile - ile / 2 - 1) / 4);
continue;
}
// cout << vec[p[i]] << ' ' << cnt.fi << ' ' << cnt.se << '\n';
akt += ((ld)cnt.fi * (cnt.fi - 1) / 4);
akt += ((ld)cnt.se * (cnt.se - 1) / 4);
// cout << fixed << setprecision(8) << akt << '\n';
}
ans = min(ans, akt);
}while(next_permutation(all(p)));
cout << fixed << setprecision(8) << ans << '\n';
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
348 KB |
found '100800.5000000000', expected '100800.5000000000', error '0.0000000000' |
2 |
Correct |
1 ms |
348 KB |
found '0.0000000000', expected '0.0000000000', error '-0.0000000000' |
3 |
Correct |
0 ms |
348 KB |
found '0.0000000000', expected '0.0000000000', error '-0.0000000000' |
4 |
Correct |
0 ms |
348 KB |
found '1.0000000000', expected '1.0000000000', error '0.0000000000' |
5 |
Correct |
0 ms |
464 KB |
found '124002.0000000000', expected '124002.0000000000', error '0.0000000000' |
6 |
Correct |
1 ms |
604 KB |
found '772893586.0000000000', expected '772893586.0000000000', error '0.0000000000' |
7 |
Correct |
1 ms |
604 KB |
found '1100977812.5000000000', expected '1100977812.5000000000', error '0.0000000000' |
8 |
Correct |
1 ms |
604 KB |
found '1249950000.5000000000', expected '1249950000.5000000000', error '0.0000000000' |
9 |
Correct |
1 ms |
604 KB |
found '1249975000.0000000000', expected '1249975000.0000000000', error '0.0000000000' |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
348 KB |
found '1.0000000000', expected '1.0000000000', error '0.0000000000' |
2 |
Correct |
1 ms |
348 KB |
found '1225.0000000000', expected '1225.0000000000', error '0.0000000000' |
3 |
Incorrect |
6 ms |
464 KB |
1st numbers differ - expected: '1023.0000000000', found: '1023.5000000000', error = '0.0004887586' |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
348 KB |
found '1.0000000000', expected '1.0000000000', error '0.0000000000' |
2 |
Correct |
1 ms |
348 KB |
found '1225.0000000000', expected '1225.0000000000', error '0.0000000000' |
3 |
Incorrect |
6 ms |
464 KB |
1st numbers differ - expected: '1023.0000000000', found: '1023.5000000000', error = '0.0004887586' |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
348 KB |
found '100800.5000000000', expected '100800.5000000000', error '0.0000000000' |
2 |
Correct |
1 ms |
348 KB |
found '0.0000000000', expected '0.0000000000', error '-0.0000000000' |
3 |
Correct |
0 ms |
348 KB |
found '0.0000000000', expected '0.0000000000', error '-0.0000000000' |
4 |
Correct |
0 ms |
348 KB |
found '1.0000000000', expected '1.0000000000', error '0.0000000000' |
5 |
Correct |
0 ms |
464 KB |
found '124002.0000000000', expected '124002.0000000000', error '0.0000000000' |
6 |
Correct |
1 ms |
604 KB |
found '772893586.0000000000', expected '772893586.0000000000', error '0.0000000000' |
7 |
Correct |
1 ms |
604 KB |
found '1100977812.5000000000', expected '1100977812.5000000000', error '0.0000000000' |
8 |
Correct |
1 ms |
604 KB |
found '1249950000.5000000000', expected '1249950000.5000000000', error '0.0000000000' |
9 |
Correct |
1 ms |
604 KB |
found '1249975000.0000000000', expected '1249975000.0000000000', error '0.0000000000' |
10 |
Correct |
0 ms |
348 KB |
found '1.0000000000', expected '1.0000000000', error '0.0000000000' |
11 |
Correct |
1 ms |
348 KB |
found '1225.0000000000', expected '1225.0000000000', error '0.0000000000' |
12 |
Incorrect |
6 ms |
464 KB |
1st numbers differ - expected: '1023.0000000000', found: '1023.5000000000', error = '0.0004887586' |
13 |
Halted |
0 ms |
0 KB |
- |