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답안 #468445

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
468445 2021-08-28T10:34:19 Z sumit_kk10 구경하기 (JOI13_watching) C++14
50 / 100
 1000 ms 16320 KB 
#include <bits/stdc++.h>
#define fast ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL)
#define ll long long int
#define ld long double
using namespace std;
const int N = 2e3 + 5;
const int MOD = 1e9 + 7;
int n, p, q, a[N], dp[N][N];

int go(int i, int small, ll mid){
    if(small > p) return INT_MAX;
    if(i == n + 1) return 0;
    if(dp[i][small] != -1)
        return dp[i][small];
    int req = INT_MAX, low = i + 1, high = n, res = n + 1;
    while(low <= high){
        int mid1 = (low + high) / 2;
        if(a[mid1] > a[i] + mid - 1){
            res = mid1;
            high = mid1 - 1;
        }
        else
            low = mid1 + 1;
    }
    req = min(req, go(res, small + 1, mid));
    low = i + 1, high = n, res = n + 1;
    while(low <= high){
        int mid1 = (low + high) / 2;
        if(a[mid1] > a[i] + 2*mid - 1){
            res = mid1;
            high = mid1 - 1;
        }
        else
            low = mid1 + 1;
    }
    req = min(req, go(res, small, mid) + 1);
    return dp[i][small] = req;
}

bool check(ll mid){
    // let dp[i][j] denote the min no. of large cameras needed when we place atmost j small cameras
    // in the prefix of i.
    memset(dp, -1, sizeof dp);
    return (go(1, 0, mid) <= q);
}

void solve(){
    cin >> n >> p >> q;
    for(int i = 1; i <= n; ++i)
        cin >> a[i];
    if(p + q >= n){
        cout << "1\n";
        return;
    }
    sort(a + 1, a + n + 1);
    ll low = 1, high = 1e12, ans;
    while(low <= high){
        ll mid = low + (high - low) / 2;
        if(check(mid)){
            ans = mid;
            high = mid - 1;
        }
        else
            low = mid + 1;
    }
    cout << ans << "\n";
}

int main(){
    fast;
    int t = 1;
    // cin >> t;
    while(t--)
        solve();
    return 0;
}

Subtask #1
50.0 / 50.0

# 결과 실행 시간 메모리 Grader output
1 Correct 81 ms 15948 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 81 ms 16032 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 85 ms 16028 KB Output is correct
8 Correct 84 ms 15948 KB Output is correct
9 Correct 82 ms 16032 KB Output is correct
10 Correct 83 ms 15928 KB Output is correct
11 Correct 89 ms 15948 KB Output is correct
12 Correct 85 ms 15940 KB Output is correct
13 Correct 84 ms 16044 KB Output is correct
14 Correct 83 ms 16032 KB Output is correct
15 Correct 82 ms 16028 KB Output is correct

Subtask #2
0 / 50.0

# 결과 실행 시간 메모리 Grader output
1 Correct 85 ms 16036 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 87 ms 16056 KB Output is correct
8 Correct 243 ms 16068 KB Output is correct
9 Correct 611 ms 16124 KB Output is correct
10 Execution timed out 1084 ms 16320 KB Time limit exceeded
11 Halted 0 ms 0 KB -