Submission #766552

#	Time	Username	Problem	Language	Result	Execution time	Memory
766552		Essa2006	Watching (JOI13_watching)	C++14	100 / 100	314 ms	15368 KiB

watching

#include<bits/stdc++.h>
using namespace std;
#define ll long long 
#define endl '\n'
#define FF first
#define SS second
#define all(a) a.begin(), a.end()
#define mod (ll)(1000000007)
const int inf=1e9;
int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    int n, p, q;
    cin>>n>>p>>q;
    if(q+p>=n)
        return cout<<1, 0;
    // p -> w
    // q -> 2*w
    vector<int>A(n);
    for(int i=0;i<n;i++){
        cin>>A[i];
    }
    sort(all(A));
    int l=0, r=1e9, ans;
    while(l<=r){
        int md=(l+r)/2;
        vector<vector<int>>Mn(n, vector<int>(q+1, inf));
        for(int i=0;i<n;i++){
            int fir2=-1, fir1=-1;
            for(int j=i;j>=0;j--){
                if(A[i]-A[j]+1>2*md){
                    fir2=j;
                    break;
                }
            }
            for(int j=i;j>=0;j--){
                if(A[i]-A[j]+1>md){
                    fir1=j;
                    break;
                }
            }
            Mn[i][0]=(fir1==-1?0:Mn[fir1][0])+1;
            for(int j=1;j<=q;j++){
                Mn[i][j]=min({Mn[i][j], (fir2==-1?0:Mn[fir2][j-1]), (fir1==-1?0:Mn[fir1][j])+1});
            }
        }
        int mn=inf;
        for(int i=0;i<=q;i++){
            mn=min(mn, Mn[n-1][i]);
        }
        if(mn<=p)
            ans=md, r=md-1;
        else
            l=md+1;
    }
    cout<<ans;
}

Compilation message (stderr)

watching.cpp: In function 'int main()':
watching.cpp:55:11: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
   55 |     cout<<ans;
      |           ^~~

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