Submission #916726

#	Time	Username	Problem	Language	Result	Execution time	Memory
916726		Dec0Dedd	Watching (JOI13_watching)	C++14	100 / 100	300 ms	32192 KiB

watching

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N = 2e3+10;
const int INF = 1e9+10;

ll a[N], n, p, q;

ll dp[N][N];
bool check(ll w) {
    for (int i=0; i<=n; ++i) {
        for (int j=0; j<=n; ++j) dp[i][j]=INF;
    }

    dp[0][0]=0;

    ll ppt=1, qpt=1;
    for (int i=1; i<=n; ++i) {
        while (a[i]-a[ppt]+1 > w) ++ppt;
        while (a[i]-a[qpt]+1 > 2*w) ++qpt;
        for (int j=1; j<=p; ++j) dp[i][j]=dp[ppt-1][j-1];
        for (int j=0; j<=p; ++j) dp[i][j]=min(dp[i][j], dp[qpt-1][j]+1);
    }

    for (int i=0; i<=p; ++i) {
        if (dp[n][i] <= q) return true;
    } return false;
} 

void solve() {
    cin>>n>>p>>q;
    for (int i=1; i<=n; ++i) cin>>a[i];
    sort(a+1, a+n+1);

    if (p+q >= n) {
        cout<<1<<"\n";
        return;
    }
    
    ll l=1, r=INF, res=INF;
    while (l <= r) {
        ll m=(l+r)/2;
        if (check(m)) res=m, r=m-1;
        else l=m+1;
    } cout<<res<<"\n";
}

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

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