oj.uz

Submission #236828

# Submission time Handle Problem Language Result Execution time Memory
236828 2020-06-03T13:50:03 Z apostoldaniel854 Watching (JOI13_watching) C++14
100 / 100
 276 ms 16120 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
#define pb push_back
#define dbg(x) cerr << #x << " " << x << "\n"



void _ (int &a, int b) {
    if (a > b)
        a = b;
}
const int N = 2000;
int dp[1 + N][1 + N];
int a[1 + N];
int n, p, q;

bool check (int w) {
    for (int i = 0; i <= n; i++)
        for (int j = 0; j <= p; j++)
            dp[i][j] = q + 1;
    dp[0][0] = 0;
    int x = 0, y = 0;
    for (int i = 1; i <= n; i++) {
        while (a[x] + w <= a[i])
            x++;
        if (x)
            x--;
        while (a[y] + 2 * w <= a[i])
            y++;
        if (y)
            y--;
        for (int j = 0; j <= p; j++) {
            if (j)
                _ (dp[i][j], dp[x][j - 1]);
            _ (dp[i][j], dp[y][j] + 1);
        }
    }
    for (int i = 0; i <= p; i++)
        if (dp[n][i] <= q)
            return true;
    return false;
}

int main () {
    cin >> n >> p >> q;
    _ (p, n);
    _ (q, n);
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    sort (a + 1, a + n + 1);
    int lb = 1, rb = (1 << 30);
    int bestW = 0;
    while (lb <= rb) {
        int mid = (lb + rb) / 2;
        if (check (mid))
            bestW = mid, rb = mid - 1;
        else
            lb = mid + 1;
    }
    cout << bestW << "\n";
    return 0;
}

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 768 KB Output is correct
2 Correct 4 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 6 ms 768 KB Output is correct
5 Correct 5 ms 768 KB Output is correct
6 Correct 6 ms 896 KB Output is correct
7 Correct 5 ms 768 KB Output is correct
8 Correct 5 ms 768 KB Output is correct
9 Correct 5 ms 768 KB Output is correct
10 Correct 5 ms 768 KB Output is correct
11 Correct 6 ms 768 KB Output is correct
12 Correct 5 ms 768 KB Output is correct
13 Correct 5 ms 768 KB Output is correct
14 Correct 5 ms 768 KB Output is correct
15 Correct 5 ms 768 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 8448 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 229 ms 16000 KB Output is correct
4 Correct 276 ms 16120 KB Output is correct
5 Correct 23 ms 8960 KB Output is correct
6 Correct 271 ms 16000 KB Output is correct
7 Correct 12 ms 8448 KB Output is correct
8 Correct 29 ms 9344 KB Output is correct
9 Correct 117 ms 14208 KB Output is correct
10 Correct 265 ms 16120 KB Output is correct
11 Correct 25 ms 9088 KB Output is correct
12 Correct 154 ms 16000 KB Output is correct
13 Correct 12 ms 8448 KB Output is correct
14 Correct 14 ms 8576 KB Output is correct
15 Correct 13 ms 8576 KB Output is correct