Submission #679035

#	Time	Username	Problem	Language	Result	Execution time	Memory
679035		sunwukong123	Cigle (COI21_cigle)	C++14	100 / 100	788 ms	288200 KiB

cigle

#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 fenv{
	int fw[MAXN];
	fenv(){
		FOR(i,0,n)fw[i]=-inf;
	}
	void update(int x, int nval) {
		for(;x<MAXN;x+=x&-x)chmax(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;
}

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 13 / 13
• Subtask 4: 15 / 15
• Subtask 5: 52 / 52