Submission #1022231

#	Time	Username	Problem	Language	Result	Execution time	Memory
1022231		amirhoseinfar1385	Shortcut (IOI16_shortcut)	C++17	31 / 100	2063 ms	604 KiB

shortcut

#include "shortcut.h"
#include<bits/stdc++.h>
using namespace std;
const long long maxn=1000000+10;
long long inf=1e16,n,c;
long long alld[maxn],mainres=inf,mxa[maxn],mxb[maxn];
vector<long long>all;
 
long long pors(long long l,long long r){
    long long b=all[r]-all[l]+c;
    long long fake=0;
    for(long long i=0;i<n;i++){
        if(i<=l){
            fake=max(fake,alld[i]+all[l]-all[i]+min(c,b-c)+mxb[r]);
            fake=max(fake,alld[i]+all[i]-(i==0?0:all[i-1])+(i==0?0:mxa[i-1]));
        }else if(i>=r){
            fake=max(fake,alld[i]+all[i]-all[r]+min(c,b-c)+mxa[l]);
            fake=max(fake,alld[i]-all[i]+all[i+1]+mxb[i+1]);
        }else{
            fake=max(fake,min(all[i]-all[l],b-(all[i]-all[l]))+mxa[l]+alld[i]);
            fake=max(fake,min(all[r]-all[i],b-(all[r]-all[i]))+mxb[r]+alld[i]);
        }
    }
    for(long long i=l;i<=r;i++){
        int h=lower_bound(all.begin(),all.end(),all[i]+b/2)-all.begin();
        for(int j=i+1;j<=r;j++){
            if(j>r||j<l){
                continue;
            }
            fake=max(fake,min(b-abs(all[j]-all[i]),abs(all[j]-all[i]))+alld[i]+alld[j]);
        }
    }
    return fake;
}
 
void solve(long long l,long long r,long long tl=0,long long tr=n-1){
    for(long long i=0;i<n;i++){
        for(long long j=i;j<n;j++){
            mainres=min(mainres,pors(i,j));
        }
    }
}
 
long long find_shortcut(int n_, std::vector<int> l, std::vector<int> d, int c_)
{
    n=n_;
    c=c_;
    all.push_back(0);
    alld[0]=d[0];
    l.push_back(0);
    for(long long i=1;i<n;i++){
        all.push_back(all.back()+l[i-1]);
        alld[i]=d[i];
    }
    for(long long i=0;i<n;i++){
        if(i!=0){
            mxa[i]=max(mxa[i-1]+l[i-1],alld[i]);
        }else{
            mxa[i]=alld[i];
        }
    }
    all[n]=all[n-1];
    for(long long i=n-1;i>=0;i--){
        mxb[i]=max(mxb[i+1]+l[i],alld[i]);
    }
    solve(0,n-1);
    return mainres;
}

Compilation message (stderr)

shortcut.cpp: In function 'long long int pors(long long int, long long int)':
shortcut.cpp:25:13: warning: unused variable 'h' [-Wunused-variable]
   25 |         int h=lower_bound(all.begin(),all.end(),all[i]+b/2)-all.begin();
      |             ^

• Subtask 1: 9 / 9
• Subtask 2: 14 / 14
• Subtask 3: 8 / 8
• Subtask 4: 0 / 7
• Subtask 5: 0 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3