Submission #1123142

#	Time	Username	Problem	Language	Result	Execution time	Memory
1123142		hainam2k9	Watching (JOI13_watching)	C++20	100 / 100	260 ms	16196 KiB

watching

#include <bits/stdc++.h>
#define tt cin.tie(0), cout.tie(0), ios_base::sync_with_stdio(0)
#define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
#define ll long long
#define ull unsigned long long
#define i128 __int128
#define db long double
#define sz(a) ((int)(a).size())
#define pb emplace_back
#define pf emplace_front
#define pob pop_back
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define ins emplace
using namespace std;
const int MOD = 1e9+7, MAXN = 1e5+5;
const string NAME = "";
int n,p,q,a[2005],dp[2005][2005];
inline int Front(int i, queue<int>& q){
    if(q.empty()) return i;
    return q.front();
}
void Print(queue<int> q){
    while(!q.empty()) cout << q.front() << " ", q.pop();
    cout << "\n";
}
bool check(int mid){
    memset(dp,0,sizeof(dp));
    queue<int> small,large;
    for(int i = 1; i<=n; ++i){
        while(!small.empty()&&a[i]-a[small.front()]+1>mid) small.pop();
        while(!large.empty()&&a[i]-a[large.front()]+1>mid<<1) large.pop();
        dp[i][0]=dp[Front(i,large)-1][0]+1;
        for(int j = 1; j<=p; ++j)
            dp[i][j]=min(dp[Front(i,small)-1][j-1],dp[Front(i,large)-1][j]+1);
        small.push(i), large.push(i);
    }
    return dp[n][p]<=q;
}
int bs(int l, int r){
    int rs=1;
    while(l<=r){
        int mid=(l+r)>>1;
        if(check(mid)) rs=mid, r=mid-1;
        else l=mid+1;
    }
    return rs;
}
int main()
{
    tt;
    if(fopen((NAME + ".INP").c_str(), "r")) fo;
    cin >> n >> p >> q;
    for(int i = 1; i<=n; ++i) cin >> a[i];
    if(p+q>=n){
        cout << 1;
        return 0;
    }
    sort(a+1,a+n+1);
    cout << bs(1,1e9);
}

Compilation message (stderr)

watching.cpp: In function 'int main()':
watching.cpp:3:19: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
watching.cpp:55:45: note: in expansion of macro 'fo'
   55 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~
watching.cpp:3:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |                                                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
watching.cpp:55:45: note: in expansion of macro 'fo'
   55 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~

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