#include <bits/stdc++.h>
using namespace std;
#define int ll
#define endl '\n' //comment for interactive
#define fast_io ios::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define pb push_back
#define re resize
#define ff first
#define ss second
#define all(x) (x).begin(), (x).end()
#define all1(x) (x).begin()+1, (x).end()
#define loop(i, n) for(int i = 0; i < n; i++)
#define loop1(i, n) for(int i = 1; i <= n; i++)
#define print(x) cout << #x << ": " << x << endl << flush
typedef long long ll;
typedef vector<int> vi;
typedef vector<double> vd;
typedef array<int, 2> ii;
typedef array<int, 3> ti;
typedef vector<ii> vii;
typedef vector<ti> vti;
typedef vector<vi> vvi;
typedef priority_queue<int> pq;
template<class T> bool ckmin(T&a, T b) { bool B = a > b; a = min(a, b); return B; }
template<class T> bool ckmax(T&a, T b) { bool B = a < b; a = max(a, b); return B; }
const int inf = 1e17;
double cst(int x) {
return (double) x * (x-1) / 4;
}
void solve() {
string s;
cin >> s;
int n = s.size();
cout << setprecision(16) << cst(n/2) + cst((n+1)/2) << endl;
// vvi pos(26);
// loop(i, n)
// pos[s[i]-'a'].pb(i);
// vi ch;
// loop(i, 26) if(!pos[i].empty())
// ch.pb(i);
// int g = ch.size();
// vi id(26);
// loop(i, g) id[ch[i]] = i;
// vi dp(1 << g, inf);
// dp[0] = 0;
// loop1(pre, 1 << g) {
// bitset<15> prev(pre);
// loop(ch, g) if(!prev[ch]) {
// int nxt = pre + 1 << ch;
// int cost = inf;
// loop(idx, n) {
// int ans = 0;
// int cnt = 0, oth = 0;
// for(int i = 0; i <= idx; i++) {
// if(prev[id[s[i]-'a']]) oth++;
// else if(id[s[i]-'a'] == ch) {
// cnt++;
// ans += oth;
// }
// }
// ans += cst(cnt);
// cnt = 0, oth = 0;
// for(int i = n; i > idx; i--) {
// if(prev[id[s[i]-'a']]) oth++;
// else if(id[s[i]-'a'] == ch) {
// cnt++;
// ans += oth;
// }
// }
// ans += cst(cnt);
// ckmin(cost, ans);
// }
// ckmin(dp[nxt], dp[pre] + cost);
// }
// }
// cout << dp[1 << g - 1] << endl;
}
signed main() {
fast_io;
int t = 1; //cin >> t;
while(t--)
solve();
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
found '100800.5000000000', expected '100800.5000000000', error '0.0000000000' |
| 2 |
Correct |
0 ms |
212 KB |
found '0.0000000000', expected '0.0000000000', error '-0.0000000000' |
| 3 |
Correct |
1 ms |
212 KB |
found '0.0000000000', expected '0.0000000000', error '-0.0000000000' |
| 4 |
Correct |
1 ms |
212 KB |
found '1.0000000000', expected '1.0000000000', error '0.0000000000' |
| 5 |
Correct |
0 ms |
212 KB |
found '124002.0000000000', expected '124002.0000000000', error '0.0000000000' |
| 6 |
Correct |
1 ms |
468 KB |
found '772893586.0000000000', expected '772893586.0000000000', error '0.0000000000' |
| 7 |
Correct |
1 ms |
468 KB |
found '1100977812.5000000000', expected '1100977812.5000000000', error '0.0000000000' |
| 8 |
Correct |
1 ms |
596 KB |
found '1249950000.5000000000', expected '1249950000.5000000000', error '0.0000000000' |
| 9 |
Correct |
1 ms |
596 KB |
found '1249975000.0000000000', expected '1249975000.0000000000', error '0.0000000000' |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
1st numbers differ - expected: '1.0000000000', found: '3.0000000000', error = '2.0000000000' |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
212 KB |
1st numbers differ - expected: '1.0000000000', found: '3.0000000000', error = '2.0000000000' |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
212 KB |
found '100800.5000000000', expected '100800.5000000000', error '0.0000000000' |
| 2 |
Correct |
0 ms |
212 KB |
found '0.0000000000', expected '0.0000000000', error '-0.0000000000' |
| 3 |
Correct |
1 ms |
212 KB |
found '0.0000000000', expected '0.0000000000', error '-0.0000000000' |
| 4 |
Correct |
1 ms |
212 KB |
found '1.0000000000', expected '1.0000000000', error '0.0000000000' |
| 5 |
Correct |
0 ms |
212 KB |
found '124002.0000000000', expected '124002.0000000000', error '0.0000000000' |
| 6 |
Correct |
1 ms |
468 KB |
found '772893586.0000000000', expected '772893586.0000000000', error '0.0000000000' |
| 7 |
Correct |
1 ms |
468 KB |
found '1100977812.5000000000', expected '1100977812.5000000000', error '0.0000000000' |
| 8 |
Correct |
1 ms |
596 KB |
found '1249950000.5000000000', expected '1249950000.5000000000', error '0.0000000000' |
| 9 |
Correct |
1 ms |
596 KB |
found '1249975000.0000000000', expected '1249975000.0000000000', error '0.0000000000' |
| 10 |
Incorrect |
0 ms |
212 KB |
1st numbers differ - expected: '1.0000000000', found: '3.0000000000', error = '2.0000000000' |
| 11 |
Halted |
0 ms |
0 KB |
- |
