Submission #944796

#	Time	Username	Problem	Language	Result	Execution time	Memory
944796		Baizho	Bigger segments (IZhO19_segments)	C++17	37 / 100	11 ms	13400 KiB

segments

    #include <bits/stdc++.h>
    using namespace std;
    #include <ext/pb_ds/assoc_container.hpp>
    #include <ext/pb_ds/tree_policy.hpp>
    using namespace __gnu_pbds;
      
    #define ordered_set tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update>
     
    // #pragma GCC optimize("Ofast,unroll-loops,fast-math")
    // #pragma GCC target("popcnt,sse3,avx")
     
     
    typedef long long ll;
    typedef unsigned long long ull;
    typedef long double ld;
    typedef pair<ll,ll> pll;
     
    #define sz size()
    #define ff first
    #define ss second
    #define all(a) a.begin(),a.end()
    #define pb push_back
     
    const int mod = ll(1e9)+7; //(b + (a%b)) % b (to mod -1%(10^9+7) correctly in c++ its -1 but its suppose to be 10^9+6
    const ll MOD = 998244353;  // (a%mod)*(binpow(b,mod-2,mod) = (a/b)%mod
    const int N = ll(5e5)+100;
    const int M = ll(2e5) + 100;
    const long long inf = 5e18;
    //const long double eps = 1e-15L;
     
    ll lcm(ll a, ll b) { return (a / __gcd(a,b))*b; }
     
    ll binpow(ll a, ll b, ll m) { ll res=1; a %= m; while(b>0){ if(b&1)res=(res * a) % m; a=(a * a) % m; b/=2; } return res%m;}
     
    void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }

    ll n, a[N], pr[N];
    pll dp[3005];

    ll getsum(ll l, ll r) {
        return pr[r] - pr[l - 1];
    }

    void Baizho() {
        cin>>n;
        for(int i = 1; i <= n; i ++) {
            cin>>a[i];
            pr[i] = pr[i - 1] + a[i];
        }
        vector<int> v;
        v.pb(0);
        for(int i = 1; i <= n; i ++) {
            int l = 0, r = v.size() - 1, j = -1;
            while(l <= r) {
                int mid = (l + r) / 2;
                if(dp[v[mid]].ss + pr[v[mid]] <= pr[i]) l = mid + 1, j = v[mid];
                else r = mid - 1;
            }
            dp[i].ff = dp[j].ff + 1;
            dp[i].ss = getsum(j + 1, i);
            while(dp[v.back()].ss + pr[v.back()] >= dp[i].ss + pr[i]) v.pop_back();
            v.pb(i);
            // for(int j = i; j >= 1; j --) {
            //     if(dp[j - 1].ff + 1 == dp[i].ff && dp[j - 1].ss <= getsum(j, i)) dp[i].ss = min(dp[i].ss, getsum(j, i));
            //     else if(dp[j - 1].ff + 1 > dp[i].ff && dp[j - 1].ss <= getsum(j, i)) dp[i] = {dp[j - 1].ff + 1, getsum(j, i)};
            // }

            // if(dp[i - 1].ff > dp[i].ff) assert(0);
        }
        cout<<dp[n].ff<<"\n";
    }
     
    signed main() {     
    //  Freopen("nondec");
        ios_base::sync_with_stdio(false);   
        cin.tie(0);cout.tie(0); 
        // precalc();
        
        int ttt = 1;
       // cin>>ttt;
     
        for(int i=1; i<=ttt; i++) {Baizho(); }
    }

Compilation message (stderr)

segments.cpp: In function 'void Freopen(std::string)':
segments.cpp:35:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |     void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }
      |                               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
segments.cpp:35:80: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |     void Freopen(string Key){ freopen((Key+".in").c_str(), "r", stdin); freopen((Key+".out").c_str(), "w", stdout); }
      |                                                                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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