#include<bits/stdc++.h>
#define ll long long
#define F first
#define S second
using namespace std;
const ll maxn=1e18;
ll n,k,bto[1000010],bhh[1000010],hhsum[1000010];
pair<ll,ll> dp[1000010];
ll cost(ll i,ll j){
if(i>=j)return maxn;
ll l=max(i,bto[i]),r=j;
return hhsum[r]-hhsum[l]-i*(r-l);
}
struct seg{
ll pos,l,r;
seg(ll _pos,ll _l,ll _r){
pos=_pos,l=_l,r=_r;
}
};
bool check(ll d){
for(int i=1;i<=n;i++)dp[i]={maxn,0};
deque<seg> sg;
sg.push_back({0,1,n});
for(int i=1;i<=n;i++){
while(sg.front().r<i)sg.pop_front();
ll pos=sg.front().pos;
dp[i]={dp[pos].F+cost(pos,i)+d,dp[pos].S+1};
while(!sg.empty()&&dp[i].F+cost(i,sg.back().l)<dp[sg.back().pos].F+cost(sg.back().pos,sg.back().l)){
sg.pop_back();
}
if(sg.empty()){
sg.push_back({i,i+1,n});
}else{
auto[pos,l,r]=sg.back();
sg.pop_back();
ll L=l,R=r;
while(L!=R){
int mid=(L+R+1)>>1;
if(dp[i].F+cost(i,mid)<dp[pos].F+cost(pos,mid)){
R=mid-1;
}else{
L=mid;
}
}
sg.push_back({pos,l,L});
if(L!=n)sg.push_back({i,L+1,n});
}
}
return dp[n].S>=k;
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
int nowa=0,nowb=0;
cin>>n>>k;
for(int i=0;i<2*n;i++){
char c;
cin>>c;
if(c=='A'){
nowa++;
bhh[nowa]=nowb;
}else{
nowb++;
bto[nowb]=nowa;
}
}
for(int i=1;i<=n;i++){
hhsum[i]=hhsum[i-1]+bhh[i];
}
ll l=0,r=maxn;
while(l!=r){
ll m=(l+r+1)>>1;
if(check(m)){
l=m;
}else{
r=m-1;
}
}
check(l);
cout<<dp[n].F-l*k<<"\n";
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Correct |
1 ms |
4440 KB |
Output is correct |
5 |
Correct |
1 ms |
4444 KB |
Output is correct |
6 |
Incorrect |
1 ms |
4444 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Correct |
1 ms |
4440 KB |
Output is correct |
5 |
Correct |
1 ms |
4444 KB |
Output is correct |
6 |
Incorrect |
1 ms |
4444 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Correct |
1 ms |
4440 KB |
Output is correct |
5 |
Correct |
1 ms |
4444 KB |
Output is correct |
6 |
Incorrect |
1 ms |
4444 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Correct |
1 ms |
4440 KB |
Output is correct |
5 |
Correct |
1 ms |
4444 KB |
Output is correct |
6 |
Incorrect |
1 ms |
4444 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
4444 KB |
Output is correct |
2 |
Correct |
1 ms |
4444 KB |
Output is correct |
3 |
Correct |
1 ms |
4444 KB |
Output is correct |
4 |
Correct |
1 ms |
4440 KB |
Output is correct |
5 |
Correct |
1 ms |
4444 KB |
Output is correct |
6 |
Incorrect |
1 ms |
4444 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |