Submission #1272626

#	Time	Username	Problem	Language	Result	Execution time	Memory
1272626		DeathIsAwe	Watching (JOI13_watching)	C++20	100 / 100	971 ms	4232 KiB

watching

#include <bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define pb push_back
#define pf push_front
#define mp make_pair
#define ll long long
int n, p, q;


bool dpcheck(int w, vector<int> sections) {
    vector<vector<int>> dp(p + 1, vector<int>(q + 1));
    dp[0][0] = 0;
    for (int i=1;i<p+1;i++) {
        if (dp[i - 1][0] == n) {
            dp[i][0] = n;
            continue;
        }
        dp[i][0] = upper_bound(sections.begin(), sections.end(), sections[dp[i - 1][0]] + w - 1) - sections.begin();
    }
    

    for (int i=1;i<q+1;i++) {
        if (dp[0][i - 1] == n) {
            dp[0][i] = n;
            continue;
        }
        dp[0][i] = upper_bound(sections.begin(), sections.end(), sections[dp[0][i - 1]] + 2*w - 1) - sections.begin();
    }


    for (int i=1;i<p+1;i++) {
        for (int j=1;j<q+1;j++) {
            if (dp[i][j - 1] == n || dp[i - 1][j] == n) {
                dp[i][j] = n;
                continue;
            }
            dp[i][j] = upper_bound(sections.begin(), sections.end(), sections[dp[i][j - 1]] + 2*w - 1) - sections.begin();
            dp[i][j] = max(dp[i][j], (int)(upper_bound(sections.begin(), sections.end(), sections[dp[i - 1][j]] + w - 1) - sections.begin()));
        }
    }
    return (dp[p][q] == n);
}


int main() {
    cin >> n >> p >> q;
    vector<int> sections(n);
    for (int i=0;i<n;i++) {
        cin >> sections[i];
    }
    sort(sections.begin(), sections.end());


    if (p + q >= n) {
        cout << 1;
    } else {
        int top = 1000000000, bottom = 0, mid;
        while (top > bottom + 1) {
            mid = (top + bottom) / 2;
            if (dpcheck(mid, sections)) {top = mid;}
            else {bottom = mid;}
        }
        cout << top;
    }
}

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