Submission #1279140

#	Time	Username	Problem	Language	Result	Execution time	Memory
1279140		hiepsimauhong	Watching (JOI13_watching)	C++20	100 / 100	447 ms	31956 KiB

watching

#include <bits/stdc++.h>

using namespace std;

#define int long long

#define FOR(I, L, R) for(int I(L) ; I <= (int)R ; ++I)
#define FOD(I, R, L) for(int I(R) ; I >= (int)L ; --I)
#define FOA(I, A) for(auto &I : A)

#define print(A,L,R) FOR(OK, L, R){if(A[OK]<=-oo / 10||A[OK]>=oo)cout<<"- ";else cout<<A[OK]<<' ';}cout<<'\n';
#define prints(A) FOA(OK, A){cout<<OK<<' ';}cout << '\n';
#define printz(A,L,R) FOR(OK, 0, L){FOR(KO, 0, R){if(A[OK][KO]>-oo&&A[OK][KO]<oo)cout<<A[OK][KO]<<' ';else cout << "- ";} cout << '\n';}cout << '\n';

#define fs first
#define sd second
#define ii pair<int,int>
#define iii pair<int, ii>
#define all(A) A.begin(), A.end()
#define quickly cin.tie(0) -> ios_base::sync_with_stdio(0);

const int N = 2000 + 5;
const int mod = 1e9 + 7;
const int oo = 1e18;

int n, k, p, q;
int dp[N][N], a[N];
int l1[N], l2[N];

int calc(int w){
        memset(dp, 0x3f, sizeof dp);

        FOR(j, 0, p){
                dp[0][j] = 0;
                FOR(i, 1, n){
                        if(j != 0) dp[i][j] = dp[l1[i] - 1][j - 1];
                        dp[i][j] = min(dp[i][j], dp[l2[i] - 1][j] + 1);
                }
        }

        return dp[n][p] <= q;
}

signed main(){ quickly
        cin >> n >> p >> q;

        FOR(i, 1, n){
                cin >> a[i];
        }

        if(p + q >= n){
                cout << 1;
                return 0;
        }

        sort(a + 1, a + 1 + n);

        int l = 1, r = a[n];
        int ans = 0;

        while(l <= r){
                int mid = (l + r) >> 1;

                int lq = 1, lp = 1;
                FOR(i, 1, n){
                        while(a[i] - mid + 1 > a[lp]){
                                ++lp;
                        }
                        while(a[i] - 2 * mid + 1 > a[lq]){
                                ++lq;
                        };
                        l1[i] = lp;
                        l2[i] = lq;
                }

                if(calc(mid)){
                        r = mid - 1;
                        ans = mid;
                }
                else{
                        l = mid + 1;
                }
        }

        cout << ans;
}

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