Submission #155447

#	Time	Username	Problem	Language	Result	Execution time	Memory
155447		kungfulon	Watching (JOI13_watching)	C++14	100 / 100	270 ms	16220 KiB

watching

#include <bits/stdc++.h>
#define rep(i,a,b) for(int i = (a);i <= (b);i++)
#define repd(i,a,b) for(int i = (a);i >= (b);i--)
#define PB push_back
#define F first
#define S second
#define Task "watching"
using namespace std;
template <class T> T read(T &a){a = 0;char c = cin.get();bool nega = 0;while(!isdigit(c) && c != '-') c = cin.get();if(c == '-') nega = 1,c = cin.get();a = c - 48;c = cin.get();while(isdigit(c)) a = a * 10 + c - 48,c = cin.get();if(nega) a = -a;return a;}
template <class T> void writep(T a){if(a > 9) writep(a / 10);cout.put(a % 10 + 48);}
template <class T> void write(T a){if(a < 0) cout.put('-'),a = -a;writep(a);cout.put(' ');}
template <class T> void writeln(T a){write(a);cout.put('\n');}
const int N = 2012;
int n,p,q;
int dp[N][N],a[N];
bool check(int w)
{
    if(n <= p + q) return 1;
    int lq = 0,lp = 0;
    rep(i,1,n)
    {
        while(a[i] - a[lp] >= w && lp < i) lp++;
        while(a[i] - a[lq] >= w*2 && lq < i) lq++;
        rep(j,0,p)
        {
            dp[i][j] = dp[max(0,lq-1)][j] + 1;
            if(j)dp[i][j] = min(dp[i][j],dp[max(0,lp-1)][j-1]);
        }
    }
    rep(i,0,p) if(dp[n][i] <= q) return 1;
    return 0;
}
int main()
{
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
//	ifstream cin (Task".inp");
//	ofstream cout (Task".out");
    cin >> n >> p >> q;
    rep(i,1,n) cin >> a[i];
    sort(a+1,a+n+1);
    int l = 0,r = 1000000007;
    while(r - l > 1)
    {
        int mid = (l + r)/2;
        if(check(mid)) r = mid;
        else l = mid;
    }
    cout << r;
	return 0;
}

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