Submission #174708

#	Time	Username	Problem	Language	Result	Execution time	Memory
174708		GoldeN	Bigger segments (IZhO19_segments)	C++17	100 / 100	101 ms	17016 KiB

segments

#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;

#define f first
#define s second
#define pb push_back
#define all(a) a.begin(),a.end()

typedef long long ll;
typedef long double ld;
typedef pair <int,int> pii;
typedef pair <ll,ll> pll;
typedef vector <ll> vl;
typedef vector <int> vi;
typedef vector <bool> vb;
typedef vector <vector <int> > vvi;
typedef vector <vector <ll> > vvl;
typedef vector <pair<int,int> > vii;
typedef vector <pair<ll,ll> > vll;

string itos(int n) {stringstream ss;ss<<n;string s=ss.str();return s;}

ll ppow(ll x,ll y,ll mod) {
    ll res=1;
    while(y) {
        if(y&1) res=res*x%mod;
        y>>=1;
        x=x*x%mod;
    }
    return res;
}

const int N=5e5+5;
const ll inf=1e18;

ll a[N],pref[N],dp[N],ind[N];



int main() {
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    int n;
    cin >> n;
    for (int i=1;i<=n;++i) {
        cin >> a[i];
    }
    pref[1]=a[1];
    for (int i=2;i<=n;++i) {
        pref[i]=pref[i-1]+a[i];
    }
    for (int i=1;i<=n;++i) {
        ind[i]=max(ind[i],ind[i-1]);
        dp[i]=dp[ind[i]]+1;
        int l=i,r=n+1;
        ll x=2*pref[i]-pref[ind[i]];
        auto it=lower_bound(pref+i,pref+n+1,x);
        int id=it-pref;
        ind[id]=i;
    }
    cout << dp[n];
}

Compilation message (stderr)

segments.cpp: In function 'int main()':
segments.cpp:55:13: warning: unused variable 'l' [-Wunused-variable]
         int l=i,r=n+1;
             ^
segments.cpp:55:17: warning: unused variable 'r' [-Wunused-variable]
         int l=i,r=n+1;
                 ^

• Subtask 1: 13 / 13
• Subtask 2: 14 / 14
• Subtask 3: 10 / 10
• Subtask 4: 36 / 36
• Subtask 5: 27 / 27