Submission #445554

#	Time	Username	Problem	Language	Result	Execution time	Memory
445554		julian33	Watching (JOI13_watching)	C++14	100 / 100	271 ms	16196 KiB

watching

#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#define deb(...) logger(#__VA_ARGS__, __VA_ARGS__)
template<typename ...Args>
void logger(string vars, Args&&... values) {
    cerr<<vars<<" = ";
    string delim="";
    (...,(cerr<<delim<<values,delim=", "));
    cerr<<"\n";
}
#else
#define deb(...) logger(#__VA_ARGS__, __VA_ARGS__)
template<typename ...Args>
void logger(string vars, Args&&... values) {}
#endif

#define pb push_back
#define sz(x) (int)(x.size())
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
template<typename T> inline void maxa(T& a,T b){a=max(a,b);}
template<typename T> inline void mina(T& a,T b){a=min(a,b);} 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int mxN=2e3+5; //make sure this is right
const int mod=1e9+7;

int dp[mxN][mxN],a[mxN],n,p,q;

bool check(int k){
    memset(dp,-1,sizeof(dp));
    dp[0][0]=0;
    for(int i=1;i<=n;i++){
        int go=lower_bound(a,a+1+n,a[i]-k+1)-a;
        int go2=lower_bound(a,a+1+n,a[i]-2*k+1)-a;
        if(go) go--;
        if(go2) go2--;
        for(int j=1;j<=p;j++){
            if(dp[go][j-1]!=-1)
                dp[i][j]=dp[i][j]==-1?dp[go][j-1]:min(dp[i][j],dp[go][j-1]);
            if(dp[go2][j]!=-1 && dp[go2][j]<q)
                dp[i][j]=dp[i][j]==-1?dp[go2][j]+1:min(dp[i][j],dp[go2][j]+1);
        }
        if(dp[go2][0]!=-1 && dp[go2][0]<q)
            dp[i][0]=dp[i][0]==-1?dp[go2][0]+1:min(dp[i][0],dp[go2][0]+1);
    }
    for(int i=0;i<=p;i++){
        if(dp[n][i]!=-1)
            return 1;
    }
    return 0;
}

int main(){
    cin.sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    #ifdef LOCAL
        freopen("input.txt","r",stdin);
        freopen("output.txt","w",stdout);
    #endif

    cin>>n>>p>>q;
    mina(p,n); mina(q,n);
    for(int i=1;i<=n;i++)
        cin>>a[i];
    sort(a,a+1+n);
    int l=1; int r=1e9;
    int ans=1e9;
    while(l<=r){
        int mid=(l+r)>>1;
        if(check(mid)){
            ans=mid; r=mid-1;
        } else{
            l=mid+1;
        }
    }
    cout<<ans<<"\n";
}

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