#include <bits/stdc++.h>
using namespace std;
#define int long long
#define FOR(i,s,e) for(int i = s; i <= (int)e; ++i)
#define DEC(i,s,e) for(int i = s; i >= (int)e; --i)
#define IAMSPEED ios_base::sync_with_stdio(false); cin.tie(0);
#ifdef LOCAL
#define db(x) cerr << #x << "=" << x << "\n"
#define db2(x, y) cerr << #x << "=" << x << " , " << #y << "=" << y << "\n"
#define db3(a,b,c) cerr<<#a<<"="<<a<<","<<#b<<"="<<b<<","<<#c<<"="<<c<<"\n"
#define dbv(v) cerr << #v << ":"; for (auto ite : v) cerr << ite << ' '; cerr <<"\n"
#define dbvp(v) cerr << #v << ":"; for (auto ite : v) cerr << "{" << ite.f << ',' << ite.s << "} "; cerr << "\n"
#define dba(a,ss,ee) cerr << #a << ":"; FOR(ite,ss,ee) cerr << a[ite] << ' '; cerr << "\n"
#define reach cerr << "LINE: " << __LINE__ << "\n";
#else
#define reach
#define db(x)
#define db2(x,y)
#define db3(a,b,c)
#define dbv(v)
#define dbvp(v)
#define dba(a,ss,ee)
#endif
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define pb push_back
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define f first
#define s second
#define g0(x) get<0>(x)
#define g1(x) get<1>(x)
#define g2(x) get<2>(x)
#define g3(x) get<3>(x)
typedef pair <int, int> pi;
typedef tuple<int,int,int> ti3;
typedef tuple<int,int,int,int> ti4;
int rand(int a, int b) { return a + rng() % (b-a+1); }
const int MOD = 1e9 + 7;
const int inf = (int)1e9 + 500;
const long long oo = (long long)1e18 + 500;
template <typename T> bool chmax(T& a, const T b) { return a<b ? a = b, 1 : 0; }
template <typename T> bool chmin(T& a, const T b) { return a>b ? a = b, 1 : 0; }
const int MAXN = 5005;
int dp[MAXN][MAXN];
int mx[MAXN][MAXN];
int n;
int A[MAXN];
int ans;
struct fw{
int fw[MAXN];
void update(int x, int nval) {
for(;x<MAXN;x+=x&-x)fw[x]+=nval;
}
int get(int x) {
int r=-inf;
for(;x;x-=x&-x)chmax(r,fw[x]);
return r;
}
} BIT[MAXN];
int32_t main()
{
cin >> n;
FOR(i,1,n) cin >> A[i];
FOR(i,0,n)mx[i][0]=mx[0][i]=-inf;
FOR(i,1,n) {
int sum = 0, same=0, lf = 0, rg = 0, idx=i;
FOR(j,i,n) { // count the equal for the previous guy here.
dp[i][j]=dp[i][j-1]; // this guy has nothing underneath
chmax(dp[i][j], dp[idx][i-1] + sum - same); // the last equal can't be counted if the previous row doesn't have a thing after this
if(i!=1)chmax(dp[i][j], BIT[i-1].get(idx-1)+ sum); // the bottom row has 1 more than this.
//mx[i][j]=max(mx[i-1][j], dp[i][j]);
BIT[j].update(i,dp[i][j]);
rg += A[j];
while(rg>lf && idx>1) {
--idx;
lf += A[idx];
}
sum += (lf == rg);
if(lf>=rg)same=(lf==rg); // there's
}
chmax(ans, dp[i][n]);
}
cout << ans;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
852 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
852 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
10 ms |
15316 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
852 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
852 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |