Submission #756711

#	Time	Username	Problem	Language	Result	Execution time	Memory
756711		dzdzx	Growing Vegetables is Fun 4 (JOI21_ho_t1)	C++14	0 / 100	2 ms	340 KiB

Main

#include <bits/stdc++.h>
#define int long long
using namespace std;
main(){
    int n;
    cin>>n;
    int a[n+1];
    for (int i=1;i<=n;i++)cin>>a[i];
    int l=-1,r=3000000001;
    while (r-l>1){
        int m=(r+l)/2;
        int pref[n+1],suff[n+1];
        int b[n+1];
        for (int i=1;i<=n;i++)b[i]=a[i];
        pref[1]=1;
        suff[n]=1;
        bool check=false;
        for (int i=2;i<=n;i++){
            if (pref[i-1]==0){
                pref[i]=0;
                continue;
            }
            if (b[i-1]+1-b[i]>m){
                pref[i]=0;
                continue;
            }
            pref[i]=1;
            if (b[i]>b[i-1])continue;
            
            b[i]=b[i-1]+1;
            
        }
        for (int i=1;i<=n;i++)b[i]=a[i];
        for (int i=n-1;i>=1;i--){
            if (suff[i+1]==0){
                suff[i]=0;
                continue;
            }
            if (b[i+1]+1-b[i]>m){
                suff[i]=0;
                continue;
            }
            suff[i]=1;
            if (b[i]>b[i+1])continue;
            
            b[i]=b[i+1]+1;            
            
        }
    //    for (int i=1;i<=n;i++)cout<<m<<" "<<pref[i]<<" "<<suff[i]<<"\n";
        if (m<0)check=false;
        for (int i=1;i<=n;i++)if (pref[i]==1 && suff[i]==1)check=true;
        if (check){
            r=m;
        }else l=m;
        
        
    }
    cout<<r;
}

Compilation message (stderr)

Main.cpp:4:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    4 | main(){
      | ^~~~

• Subtask 1: 0 / 40
• Subtask 2: 0 / 60