Submission #200697

#	Time	Username	Problem	Language	Result	Execution time	Memory
200697		BThero	Gap (APIO16_gap)	C++17	100 / 100	79 ms	2796 KiB

gap

// Why am I so dumb? :c
// chrono::system_clock::now().time_since_epoch().count()
                                                  
#include<bits/stdc++.h>
#include "gap.h"

//#include<ext/pb_ds/assoc_container.hpp>
//#include<ext/pb_ds/tree_policy.hpp>

#define pb push_back
#define mp make_pair

#define all(x) (x).begin(), (x).end()

#define fi first
#define se second

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;   
typedef pair<int, int> pii;
//template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const ll INF = (ll)1e18;

ll subtask1(int n) {
    ll l, r, ans = 0;
    MinMax(0, INF, &l, &r);
    int met = 2; 

    while (met < n) {
        ll nl, nr;
        MinMax(l + 1, r - 1, &nl, &nr);
        ans = max(ans, nl - l);
        ans = max(ans, r - nr);
        l = nl;
        r = nr;
        met += 2;
    }

    ans = max(ans, r - l);
    return ans;
}

ll subtask2(int n) {
    ll ourL, ourR;
    MinMax(0, INF, &ourL, &ourR);

    ll A = (ourR - ourL + 1) / (n + 1);
    ll B = (ourR - ourL + 1) % (n + 1);
    ll ret = 0;
    ll ptr = ourL;
    vector<ll> L(n + 1), R(n + 1);
    L[0] = ourL;
    R[n] = ourR;

    for (int i = 0; i <= n; ++i) {
        ll cur = A + (i + B > n);

        if (i > 0 && i < n) {
            MinMax(ptr, ptr + cur - 1, &L[i], &R[i]);
        }
        else if (i == 0) {
            if (ptr + 1 > ptr + cur - 1) {
                R[i] = L[i];
            }
            else {
                ll tmp;
                MinMax(ptr + 1, ptr + cur - 1, &tmp, &R[i]);

                if (tmp == -1) {
                    R[i] = L[i];
                }
            }        
        }
        else {
            if (ptr > ptr + cur - 2) {
                L[i] = R[i];
            }
            else {
                ll tmp;
                MinMax(ptr, ptr + cur - 2, &L[i], &tmp);

                if (tmp == -1) {
                    L[i] = R[i];
                }
            }
        }

        ptr += cur;                
    }

    ptr = -1;

    for (int i = 0; i <= n; ++i) {
        if (L[i] != -1) {
            if (ptr != -1) {
                ret = max(ret, L[i] - ptr);
            }

            ptr = R[i];
        }
    }

    ptr = -1;

    for (int i = n; i >= 0; --i) {
        if (R[i] != -1) {
            if (ptr != -1) {
                ret = max(ret, ptr - R[i]);
            }

            ptr = L[i];
        }        
    }

    return ret;    
}

ll findGap(int T, int N) {
    if (T == 1) {
        return subtask1(N);            
    }
    else {
        return subtask2(N);    
    }
}

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70