oj.uz

Submission #719084

# Submission time Handle Problem Language Result Execution time Memory
719084 2023-04-05T10:20:16 Z thimote75 Watching (JOI13_watching) C++14
100 / 100
 257 ms 16012 KB 
#include <bits/stdc++.h>

using namespace std;

#define MAX_N 2000
#define inf 1e9

int nbEvents, nbSmall, nbLarge;
vector<int> eventTime;

vector<int> target_w;
vector<int> target_2w;

int dp[MAX_N][MAX_N];
int get_dp (int node, int picture) {
    if (picture == -1) return inf;
    if (node == -1) return 0;
    return dp[node][picture];
}

bool test_w (int w) {
    int l = -1;
    for (int r = 0; r < nbEvents; r ++) {
        while (eventTime[l + 1] + w <= eventTime[r])
            l ++;
        
        target_w[r] = l;
    }

    l = -1;
    for (int r = 0; r < nbEvents; r ++) {
        while (eventTime[l + 1] + 2 * w <= eventTime[r])
            l ++;
        
        target_2w[r] = l;
    }

    for (int i = 0; i < nbEvents; i ++) {
        for (int j = 0; j <= nbLarge; j ++) {
            dp[i][j] = min(
                get_dp(target_w[i], j) + 1,
                get_dp(target_2w[i], j - 1)
            );
        }
    }

    int min_p = inf;
    for (int j = 0; j <= nbLarge; j ++)
        min_p = min(min_p, dp[nbEvents - 1][j]);
    
    return min_p <= nbSmall;
}

int compute_w () {
    if (nbSmall + nbLarge >= nbEvents) return 1;

    int a = 0;
    int b = inf;

    while (b - a > 1) {
        int wc = (a + b) >> 1;

        if (test_w(wc)) b = wc;
        else a = wc;
    }
    
    return b;
}

int main () {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> nbEvents >> nbSmall >> nbLarge;

    eventTime.resize(nbEvents);
    target_w .resize(nbEvents);
    target_2w.resize(nbEvents);

    for (int iE = 0; iE < nbEvents; iE ++)
        cin >> eventTime[iE];
    
    sort(eventTime.begin(), eventTime.end());

    cout << compute_w();
}

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 724 KB Output is correct
2 Correct 1 ms 324 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 324 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 724 KB Output is correct
8 Correct 1 ms 724 KB Output is correct
9 Correct 1 ms 724 KB Output is correct
10 Correct 1 ms 716 KB Output is correct
11 Correct 1 ms 724 KB Output is correct
12 Correct 1 ms 708 KB Output is correct
13 Correct 1 ms 724 KB Output is correct
14 Correct 1 ms 596 KB Output is correct
15 Correct 1 ms 596 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 8276 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 6 ms 8276 KB Output is correct
8 Correct 109 ms 14248 KB Output is correct
9 Correct 22 ms 9172 KB Output is correct
10 Correct 18 ms 9112 KB Output is correct
11 Correct 257 ms 16012 KB Output is correct
12 Correct 142 ms 16000 KB Output is correct
13 Correct 7 ms 8404 KB Output is correct
14 Correct 6 ms 8276 KB Output is correct
15 Correct 7 ms 8404 KB Output is correct