Submission #863682

#	Time	Username	Problem	Language	Result	Execution time	Memory
863682		Jalppatel1428	Bigger segments (IZhO19_segments)	C++14	0 / 100	1 ms	348 KiB

segments

#include<bits/stdc++.h>
using namespace std;

#define ll long long int
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define deb(x) cout << #x << "=" << x << endl
#define deb2(x, y) cout << #x << "=" << x << "," << #y << "=" << y << endl

const ll N=5005;
const ll mod=1e9+7;

void solve()
{

     int n;
    cin>>n;
    vector<int>a(n),prf(n+1);
    for(int i=0;i<n;i++)
    {
        cin>>a[i];
        prf[i+1]=a[i]+prf[i];
    }
    vector<pair<int,int>>dp(n+1,{-1e9,0});
    dp[0]={0,0};
    pair<int,int> tmp={0,0};
    for(int i=0;i<n;i++)
    {
        if(dp[i]==(pair<int,int>){-1e9,0}){
            dp[i]={tmp.first,tmp.second+(a[i])};
            tmp.second+=a[i];
        }
        else{
            tmp=dp[i];
        }
        ll l = i+1, r = n, ans = n+1;
        //binary search for finding the shortest ending index
        while(l <= r)
        {
            int mid = (l + r) >> 1;
            int loss=0;
            loss=dp[i].second;

            if(prf[mid] - prf[i] >= dp[i].second)
            {
                ans = mid; r = mid - 1;
            }else{
                l = mid + 1;
            }
        }
        if(ans==n+1)continue;
        pair<ll,ll> opt1=dp[ans];
        pair<ll,ll> opt2={dp[i].first+1,prf[ans] - prf[i]};
                
        dp[ans].first=max(opt1.first,opt2.first);

        // if opt1.first==opt2.first  then min value segment is preferable

        if(dp[ans].first==opt2.first)  
        {
            dp[ans].second=opt2.second;
        }
        else
        {
            dp[ans].second=opt1.second;
        }

    }
    int ans=0;
    for(int i=0;i<=n;i++){
        ans=max(ans,dp[i].first);
    }
    cout<<ans<<endl;

}

int main() {
    // #ifndef ONLINE_JUDGE
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);
    // #endif
    

    IOS;
    ll T;
    T=1;
    // cin >> T;
    while(T--){
    
    solve();
    }

    return 0;
}

Compilation message (stderr)

segments.cpp: In function 'void solve()':
segments.cpp:40:17: warning: variable 'loss' set but not used [-Wunused-but-set-variable]
   40 |             int loss=0;
      |                 ^~~~

• Subtask 1: 0 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27