Submission #1084029

#	Time	Username	Problem	Language	Result	Execution time	Memory
1084029		MrPavlito	Watching (JOI13_watching)	C++17	100 / 100	277 ms	16220 KiB

watching

#include <bits/stdc++.h>
//#define int long long
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define sc second
#define endl "\n"
#define pii pair<int,int>

using namespace std;

const int MAXN = 2e3+5;
const int mod7 = 1e9+7;
const long long inf = 1e18;

int n,p,q;
vector<int> niz;
int dp[MAXN][MAXN];

bool solve(int mid)
{
    memset(dp, -1, sizeof(dp));
    for(int i=0; i<=p; i++)
    {
        for(int j=0; j<=q; j++)
        {
            if(i==0 && j == 0)continue;
            else if(i==0)
            {
                int index = dp[i][j-1]+1;
                int tr = niz[index] + mid+mid-1;
                int poz = upper_bound(all(niz), tr) - niz.begin()-1;
                dp[i][j] = poz;
            }
            else if(j == 0)
            {
                int index = dp[i-1][j]+1;
                int tr = niz[index] +mid-1;
                int poz = upper_bound(all(niz), tr) - niz.begin()-1;
                dp[i][j] = poz;
            }
            else
            {
                int index1 = dp[i][j-1]+1;
                int tr = niz[index1] + mid+mid-1;
                int poz = upper_bound(all(niz), tr) - niz.begin()-1;
                int index2 = dp[i-1][j]+1;
                int tr2 = niz[index2] + mid-1;
                int poz2 = upper_bound(all(niz), tr2) - niz.begin()-1;
                dp[i][j] = max(poz, poz2);
            }
            //cout << dp[i][j] << " ";
            if(dp[i][j]>=n-1)return 1;
        }
        //cout << endl;
    }
    return 0;

}

signed main()
{
    ios_base::sync_with_stdio(false),cin.tie(0), cout.tie(0);
    int tt=1;
    //cin >> tt;
    while(tt--)
    {
        cin >> n >> p >> q;
        niz.resize(n);
        p = min(p,n);
        q = min(q,n);
        for(int i=0; i<n; i++)cin >> niz[i];
        sort(all(niz));
        int l = 1; int r = 1e9+1;
        int rez = r;
        if(p+q>= n)
        {
            cout << 1 << endl;
            return 0;
        }
        while(l<=r)
        {
            int mid = l+r>>1;
            if(solve(mid))
            {
                rez = mid;
                r = mid-1;
            }
            else l = mid+1;
        }
        cout << rez << endl;
    }
}

Compilation message (stderr)

watching.cpp: In function 'int main()':
watching.cpp:84:24: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   84 |             int mid = l+r>>1;
      |                       ~^~

• Subtask 1: 50 / 50
• Subtask 2: 50 / 50