Submission #1270623

#	Time	Username	Problem	Language	Result	Execution time	Memory
1270623		raymoo_	Hacker (BOI15_hac)	C++17	100 / 100	294 ms	188296 KiB

hac

#include<bits/stdc++.h>
using namespace std; 
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define umap unordered_map
#define prq priority_queue
#define vect vector
#define rs resize
#define bend(v) v.begin(),v.end()
#define pob pop_back
#define pof pop_front
#define lwb lower_bound
#define upb upper_bound
#define pii pair<int,int>
#define nextl cout << '\n'
#define el '\n'
#define deb cout<<"\nok\n";return 
#define ll long long
#define int long long
#define dbl long double
#define popcnt __builtin_popcount
#define ctz __builtin_ctz
#define FILE "ellencute"
 
const ll INF=902337203695775807, N=2e5+69, MOD=1e9+7;    
 
void ffopen(){
    if(fopen(FILE".inp", "r")){
        freopen(FILE".inp", "r", stdin);
        freopen(FILE".out", "w", stdout);
    }else if(fopen("ellencute.inp", "r")){
        freopen("ellencute.inp", "r", stdin);
        freopen("ellencute.out", "w", stdout);
    }
}

int pm(int a,const int b=1e9+7){return ((a%b)+b)%b;}
int sq(int x){return x*x;}
ll __lcm(ll a, ll b, const ll lim=LLONG_MAX){
    if(a == -1 || b == -1)return -1;
    ll g = __gcd(a,b);
    if(b/g > lim/a)return -1;
    return (a/g)*b;
}

int lg2(int i) {
    return i ? __builtin_clzll(1) - __builtin_clzll(i) : -1;
}

int spt[1000005][21];

void sol(){
    int n;
    cin >> n;
    int a[n*2], pfs[n*2], g[n*2];
    for(int i=0;n>i;i++){
        cin >> a[i];
        a[i+n] = a[i];
    }
    partial_sum(a, a+n*2, pfs);
    
    auto gs = [&](int l, int r){
        if(l > r) return pfs[r] + pfs[n-1] - pfs[l-1];
        return pfs[r] - (l?pfs[l-1]:0);
    };

    int s = (n+1)/2, ans = -INF;

    for(int i=0;n*2>i;i++) g[i] = spt[i][0] = gs(i, (i+s-1)%(2*n));

    for(int b=1;21>b;b++){
        for(int i=0;n*2>i+(1<<(b-1));i++) 
            spt[i][b] = min(spt[i][b-1], spt[i+(1<<(b-1))][b-1]);
    }

    auto get = [&](int l, int r){
        int b = lg2(r-l+1);
        return min(spt[l][b], spt[r-(1<<b)+1][b]);
    };
    


    // ans = max(ans, );

    for(int j=s-1;n+s-1>j;j++){
        // cout << i << ' ' << min(gs(i, (i+s-1)%n), gs(pm(i-s+1, n), i)) << el;
        // while(dq.size() && dq.front()+s-1 < j) dq.pof();
        // // if(j==2) cout << dq.size() << el;
        // while(dq.size() && g[dq.back()] >= g[j]) dq.pob();
        
        // // if(j == 1) cout << fumo << ' ' << gs(0) << el;
        // // if(12 == fumo) cout << j << ' ' << gs(0, 0+s-1) << el;
        // cout << j << ' ' << g[dq.back()] << el;
        ans = max(ans, get(j-s+1, j));
    }
    cout << ans;
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    ffopen();
    int t=1;
    //cin >> t;
    while(t--)sol();
}
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*/

Compilation message (stderr)

hac.cpp: In function 'void ffopen()':
hac.cpp:31:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |         freopen(FILE".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
hac.cpp:32:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |         freopen(FILE".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
hac.cpp:34:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |         freopen("ellencute.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
hac.cpp:35:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |         freopen("ellencute.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 40 / 40