#include <bits/stdc++.h>
#include <bits/extc++.h>
#define StarBurstStream ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define iter(a) a.begin(), a.end()
#define riter(a) a.rbegin(), a.rend()
#define lsort(a) sort(iter(a))
#define gsort(a) sort(riter(a))
#define pb(a) push_back(a)
#define eb(a) emplace_back(a)
#define pf(a) push_front(a)
#define ef(a) emplace_front(a)
#define pob pop_back()
#define pof pop_front()
#define mp(a, b) make_pair(a, b)
#define F first
#define S second
#define mt make_tuple
#define gt(t, i) get<i>(t)
#define tomax(a, b) ((a) = max((a), (b)))
#define tomin(a, b) ((a) = min((a), (b)))
#define topos(a) ((a) = (((a) % MOD + MOD) % MOD))
#define uni(a) a.resize(unique(iter(a)) - a.begin())
#define printv(a, b) {bool pvaspace=false; \
for(auto pva : a){ \
if(pvaspace) b << " "; pvaspace=true;\
b << pva;\
}\
b << "\n";}
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<ld, ld>;
using tiii = tuple<int, int, int>;
const ll MOD = 1000000007;
const ll MAX = 2147483647;
template<typename A, typename B>
ostream& operator<<(ostream& o, pair<A, B> p){
return o << '(' << p.F << ',' << p.S << ')';
}
ll ifloor(ll a, ll b){
if(b < 0) a *= -1, b *= -1;
if(a < 0) return (a - b + 1) / b;
else return a / b;
}
ll iceil(ll a, ll b){
if(b < 0) a *= -1, b *= -1;
if(a > 0) return (a + b - 1) / b;
else return a / b;
}
int M;
int S;
ll L;
vector<ll> dp;
void waassert(bool t){
return;
if(t) return;
cout << "OAO\n";
exit(0);
}
void upd_pos(int sz, ll cnt, int t){
if(cnt == 0) return;
waassert(sz > 0 && cnt > 0);
vector<deque<pll>> dq(sz);
for(int i = 0; i <= 2 * S; i++){
int id = i % sz;
ll tmp = dp[i] - i / sz * t;
while(!dq[id].empty() && dq[id].back().S <= tmp) dq[id].pob;
dq[id].eb(mp(i, tmp));
while(!dq[id].empty() && dq[id].front().F / sz < i / sz - cnt) dq[id].pof;
dp[i] = max(dp[i], dq[id].front().S + i / sz * t);
}
/*cerr << "upd_pos " << sz << " " << cnt << "\n";
printv(dp, cerr);*/
}
void upd_neg(int sz, ll cnt, int t){
if(cnt == 0) return;
waassert(sz > 0 && cnt > 0);
assert(t == 1);
vector<deque<pll>> dq(sz);
for(int i = 2 * S; i >= 0; i--){
int id = i % sz;
ll tmp = dp[i] + i / sz * t;
while(!dq[id].empty() && dq[id].back().S <= tmp) dq[id].pob;
dq[id].eb(mp(i, tmp));
while(!dq[id].empty() && dq[id].front().F / sz > i / sz + cnt) dq[id].pof;
dp[i] = max(dp[i], dq[id].front().S - i / sz * t);
}
/*cerr << "upd_neg " << sz << " " << cnt << "\n";
printv(dp, cerr);*/
}
int main(){
StarBurstStream
cin >> M;
cin >> L;
ll sum = 0;
ll total = 0;
vector<ll> _a(2 * M + 1), _b(2 * M + 1);
function<ll&(int)> a = [&](int x) -> ll&{
waassert(M + x >= 0 && M + x <= 2 * M);
return _a[M + x];
};
function<ll&(int)> b = [&](int x) -> ll&{
waassert(M + x >= 0 && M + x <= 2 * M);
return _b[M + x];
};
for(int i = -M; i <= M; i++){
cin >> a(i);
sum += a(i) * i;
}
sum = 0;
/*if(sum <= L){
for(int i = -M; i < 0; i++){
swap(a(i), a(-i));
}
L = -L;
}
int p = -M - 1;
sum = 0;
for(int i = -M; i <= M; i++){
sum += a(i) * i;
if(sum <= L) p = i;
}
sum = 0;
for(int i = -M; i <= p; i++){
sum += a(i) * i;
b(i) = a(i);
total += b(i);
}
if(p < M){
b(p + 1) = (L - sum) / (p + 1);
sum += b(p + 1) * (p + 1);
total += b(p + 1);
}*/
total = a(0);
/*cerr << "test " << sum << " " << L << " " << L - sum << "\n";
printv(_a, cerr);
printv(_b, cerr);*/
S = max(M * M, 10000);
dp.resize(2 * S + 1, -(1LL << 60));
dp[S] = 0;
//printv(dp, cerr);
for(int i = -M; i <= M; i++){
if(i == 0) continue;
if(i < 0){
upd_pos(-i, b(i), -1);
upd_neg(-i, a(i) - b(i), 1);
}
else{
upd_pos(i, a(i) - b(i), 1);
upd_neg(i, b(i), -1);
}
}
ll ans = L - sum > S || L - sum < -S ? -(1LL << 60) : dp[S + L - sum];
if(ans < -1e9) cout << "impossible\n";
else cout << total + ans << "\n";
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
468 KB |
Output is correct |
2 |
Correct |
2 ms |
468 KB |
Output is correct |
3 |
Correct |
2 ms |
468 KB |
Output is correct |
4 |
Correct |
6 ms |
468 KB |
Output is correct |
5 |
Correct |
52 ms |
528 KB |
Output is correct |
6 |
Incorrect |
54 ms |
544 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
468 KB |
Output is correct |
2 |
Correct |
2 ms |
468 KB |
Output is correct |
3 |
Correct |
2 ms |
468 KB |
Output is correct |
4 |
Correct |
6 ms |
468 KB |
Output is correct |
5 |
Correct |
52 ms |
528 KB |
Output is correct |
6 |
Incorrect |
54 ms |
544 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
468 KB |
Output is correct |
2 |
Incorrect |
16 ms |
596 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
468 KB |
Output is correct |
2 |
Incorrect |
16 ms |
596 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
468 KB |
Output is correct |
2 |
Incorrect |
16 ms |
596 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
468 KB |
Output is correct |
2 |
Correct |
2 ms |
468 KB |
Output is correct |
3 |
Correct |
2 ms |
468 KB |
Output is correct |
4 |
Correct |
6 ms |
468 KB |
Output is correct |
5 |
Correct |
52 ms |
528 KB |
Output is correct |
6 |
Incorrect |
54 ms |
544 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
468 KB |
Output is correct |
2 |
Incorrect |
16 ms |
596 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
468 KB |
Output is correct |
2 |
Correct |
2 ms |
468 KB |
Output is correct |
3 |
Correct |
2 ms |
468 KB |
Output is correct |
4 |
Correct |
6 ms |
468 KB |
Output is correct |
5 |
Correct |
52 ms |
528 KB |
Output is correct |
6 |
Incorrect |
54 ms |
544 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
468 KB |
Output is correct |
2 |
Incorrect |
16 ms |
596 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
468 KB |
Output is correct |
2 |
Correct |
2 ms |
468 KB |
Output is correct |
3 |
Correct |
2 ms |
468 KB |
Output is correct |
4 |
Correct |
6 ms |
468 KB |
Output is correct |
5 |
Correct |
52 ms |
528 KB |
Output is correct |
6 |
Incorrect |
54 ms |
544 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |