oj.uz

Submission #373359

# Submission time Handle Problem Language Result Execution time Memory
373359 2021-03-04T09:20:57 Z BartolM Watching (JOI13_watching) C++17
100 / 100
 667 ms 16300 KB 
#include <bits/stdc++.h>

using namespace std;

#define X first
#define Y second
#define mp make_pair
#define pb push_back
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <int, pii> pip;
typedef pair <pii, int> ppi;
typedef pair <ll, ll> pll;

const int INF=0x3f3f3f3f;
const int N=2005;

int n, A, B;
int p[N];
int dp[N][N];
int nx_w[N], nx_2w[N];

int rek(int pos, int kol) {
    if (kol>A) return INF;
    if (pos>=n) return 0;

    int &ret=dp[pos][kol];
    if (ret!=-1) return ret;

    ret=rek(nx_w[pos], kol+1);
    ret=min(ret, rek(nx_2w[pos], kol)+1);
    return ret;
}

int check(int w) {
    for (int i=0; i<n; ++i) {
        nx_w[i]=nx_2w[i]=i+1;
        for (int j=i+1; j<n; ++j) {
            if (p[j]-p[i]<w) nx_w[i]=j+1;
            if (p[j]-p[i]<2*w) nx_2w[i]=j+1;
        }
    }
    memset(dp, -1, sizeof dp);
    return rek(0, 0)<=B;
}

void solve() {
    sort(p, p+n);
    int lo=1, hi=1e9+3, mid;
    while (lo<hi) {
        mid=(lo+hi)/2;
        if (check(mid)) hi=mid;
        else lo=mid+1;
    }
    printf("%d\n", lo);
}

void load() {
    scanf("%d %d %d", &n, &A, &B);
    for (int i=0; i<n; ++i) scanf("%d", p+i);
}

int main() {
    load();
    solve();
    return 0;
}

Compilation message

watching.cpp: In function 'void load()':
watching.cpp:59:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   59 |     scanf("%d %d %d", &n, &A, &B);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
watching.cpp:60:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   60 |     for (int i=0; i<n; ++i) scanf("%d", p+i);
      |                             ~~~~~^~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 65 ms 16108 KB Output is correct
2 Correct 67 ms 16108 KB Output is correct
3 Correct 65 ms 16108 KB Output is correct
4 Correct 66 ms 16108 KB Output is correct
5 Correct 66 ms 16108 KB Output is correct
6 Correct 67 ms 16256 KB Output is correct
7 Correct 71 ms 16108 KB Output is correct
8 Correct 67 ms 16236 KB Output is correct
9 Correct 67 ms 16108 KB Output is correct
10 Correct 65 ms 16108 KB Output is correct
11 Correct 68 ms 16108 KB Output is correct
12 Correct 67 ms 16108 KB Output is correct
13 Correct 64 ms 16236 KB Output is correct
14 Correct 67 ms 16000 KB Output is correct
15 Correct 66 ms 16120 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 128 ms 16108 KB Output is correct
2 Correct 66 ms 16108 KB Output is correct
3 Correct 604 ms 16236 KB Output is correct
4 Correct 618 ms 16236 KB Output is correct
5 Correct 208 ms 16236 KB Output is correct
6 Correct 667 ms 16236 KB Output is correct
7 Correct 146 ms 16256 KB Output is correct
8 Correct 203 ms 16108 KB Output is correct
9 Correct 312 ms 16108 KB Output is correct
10 Correct 650 ms 16236 KB Output is correct
11 Correct 213 ms 16236 KB Output is correct
12 Correct 554 ms 16300 KB Output is correct
13 Correct 144 ms 16108 KB Output is correct
14 Correct 144 ms 16236 KB Output is correct
15 Correct 145 ms 16108 KB Output is correct