#include <bits/stdc++.h>
#define MAX 300005
#define MOD (ll)(1048573)
#define INF (ll)(1e12)
#define inf (int)(1e9)
#define eps (double)(1e-8)
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
int tt, N, K;
string str;
int cnt[MAX], pos[MAX], can[MAX], q[MAX], k[MAX];
ll dp[MAX], sum[MAX];
ll cost(ll i, ll j) {
return max(sum[j] - sum[pos[i - 1] - 1] - (j - pos[i - 1] + 1) * (i - 1), 0ll);
}
ll func(ll i, ll j) {
return dp[i] + cost(i + 1, j);
}
int cross(int i, int j) {
int lo = j, hi = N + 1;
while(lo + 1 < hi) {
int mid = (lo + hi) >> 1;
if(func(i, mid) <= func(j, mid)) lo = mid;
else hi = mid;
}
return lo;
}
void monotoneQueue(ll lambda) {
int str = 0, ed = 1;
q[0] = 0; can[0] = N;
for(int i = 1; i <= N; ++i) {
while(can[str] < i) ++str;
dp[i] = func(q[str], i) + lambda; k[i] = k[q[str]] + 1;
while(str + 1 < ed && can[ed - 2] >= cross(q[ed - 1], i)) --ed;
can[ed - 1] = cross(q[ed - 1], i); q[ed] = i; can[ed] = N;
++ed;
}
return;
}
ll alienTrick() {
ll lo = 0, hi = INF;
while(lo + 1 < hi) {
ll mid = (lo + hi) >> 1;
monotoneQueue(mid);
if(k[N] >= K) lo = mid;
else hi = mid;
}
return lo;
}
int main() {
ios::sync_with_stdio(0);
cin.tie(NULL);
cin >> N >> K >> str;
for(int i = 0, tmp = 0, p = 0; i < 2 * N; ++i) {
if(str[i] == 'A') cnt[++p] = tmp;
else ++tmp;
}
for(int i = 0, j = 1; i <= N; ++i) {
while(j <= N && cnt[j] < i) ++j;
pos[i] = max(i + 1, j);
}
for(int i = 1; i <= N; ++i) sum[i] = sum[i - 1] + cnt[i];
ll lambdaOpt = alienTrick();
monotoneQueue(lambdaOpt);
cout << dp[N] - K * lambdaOpt;
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 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 |
460 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 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 |
460 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 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 |
460 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 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 |
460 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 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 |
460 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |