#include <bits/stdc++.h>
using namespace std;
#define file ""
#define mp make_pair
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define getbit(x, i) (((x) >> (i)) & 1)
#define bit(x) (1LL << (x))
#define popcount __builtin_popcountll
mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) {
return l + rd() % (r - l + 1);
}
const int N = 1e6 + 5;
const int mod = (int)1e9 + 7; // 998244353;
const int lg = 25; // lg + 1
const int oo = 1e9;
const long long ooo = 1e18;
template<class X, class Y> bool mini(X &a, Y b) {
return a > b ? (a = b, true) : false;
}
template<class X, class Y> bool maxi(X &a, Y b) {
return a < b ? (a = b, true) : false;
}
void add(int &a, int b) {
a += b;
if (a >= mod) a -= mod;
if (a < 0) a += mod;
}
int n;
long long a[N];
int f[N], pos[N];
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
// freopen(file".inp", "r", stdin);
// freopen(file".out", "w", stdout);
cin >> n;
for (int i = 1; i <= n; ++i) {
cin >> a[i];
a[i] += a[i - 1];
}
for (int i = 1; i <= n; ++i) {
pos[i] = max(pos[i - 1], pos[i]);
f[i] = f[pos[i]] + 1;
int l = i, r = n, nxt = 0;
while (l <= r) {
int mid = (l + r) / 2;
if (a[mid] - a[i] >= a[i] - a[pos[i]]) {
nxt = mid;
r = mid - 1;
} else l = mid + 1;
}
pos[nxt] = i;
}
cout << f[n];
return 0;
}
/*
s[i] - s[j] >= s[j] - s[k] -> binary search
*/
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
2392 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
2392 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
108 ms |
25940 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
9 ms |
9816 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
2392 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
2392 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |