#include<bits/stdc++.h>
#define ll long long
#define pll pair<ll, ll>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ld long double
using namespace std;
const ll inf=2e9, maxn=1e6;
ll pre[maxn], to[maxn];
ll n, k;
struct Line
{
ll a=inf, b=inf, idx;
Line(){}
Line(ll idx): idx(idx){}
Line(ll a, ll b): a(a), b(b){}
pll ask(ll x)
{
if (a==inf) return {inf*inf, idx};
return {a*x+b, idx};
}
};
struct Node
{
Line A;
Node *l, *r;
Node(){}
Node(ll idx): A(Line(idx)){}
};
Node *root=new Node();
struct Lichao
{
void addline(Line A, ll idx)
{
ll Start=-inf, End=inf;
Node *i=root;
while (1)
{
ll mid=(Start+End)/2;
bool l=A.ask(Start)<i->A.ask(Start);
bool m=A.ask(mid)<i->A.ask(mid);
if (m) swap(A, i->A);
if (Start+1!=End)
{
if (l!=m)
{
if (!i->l)
i->l=new Node(idx);
i=i->l;
End=mid;
}
else
{
if (!i->r)
i->r=new Node(idx);
i=i->r;
Start=mid;
}
}
else break;
}
}
pll query(ll x)
{
Node *i=root;
ll Start=-inf, End=inf;
pll ans={inf*inf, 0};
while (1)
{
ll mid=(Start+End)/2;
ans=min(ans, i->A.ask(x));
if (x<mid && i->l)
{
i=i->l;
End=mid;
}
else if (x>=mid && i->r)
{
i=i->r;
Start=mid;
}
else break;
}
return ans;
}
};
ll cost(ll j, ll i)
{
if (to[j]>i) return 0;
return (pre[i]-i*j)-(pre[to[j]-1]-(to[j]-1)*j);
}
pll solve(ll C)
{
vector <ll> dp(n+1, inf*inf), cnt(n+1, 0);
dp[0]=0;
for (ll i=1; i<=n; i++)
for (ll j=0; j<i; j++)
if (dp[j]+cost(j, i)+C<dp[i])
dp[i]=dp[j]+cost(j, i)+C, cnt[i]=cnt[j]+1;
return {dp[n]-cnt[n]*C, cnt[n]};
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n >> k;
string s; cin >> s;
ll x=0, y=0, crr=1;
for (ll i=0; i<n*2; i++)
{
if (s[i]=='A')
x++, pre[x]=pre[x-1]+y;
else y++;
}
for (ll i=1; i<=n; i++)
while (crr<=pre[i]-pre[i-1])
to[crr]=i, crr++;
while (crr<=n) to[crr]=n+1, crr++;
for (ll i=1; i<=n; i++)
if (to[i]<=i)
to[i]=i+1;
ll lo=0, hi=n*n;
while (hi>lo)
{
ll mid=(lo+hi)/2;
if (solve(mid).se<=k)
hi=mid;
else lo=mid+1;
}
cout << solve(lo).fi;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 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 |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 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 |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 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 |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 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 |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 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 |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |