Submission #836312

#	Time	Username	Problem	Language	Result	Execution time	Memory
836312		oscar1f	Shortcut (IOI16_shortcut)	C++17	31 / 100	2079 ms	4284 KiB

shortcut

#include<bits/stdc++.h>
#include "shortcut.h"

using namespace std;
using ll=long long;

const ll MAX_SOM=3000+5,INFINI=(ll)1000*1000*1000*1000*1000*1000,DECA=(1<<12);
ll nbSom,prixNouv,rep;
ll cumu[MAX_SOM];
ll distStat[MAX_SOM];
ll arbreMax[2*DECA],memo[MAX_SOM][MAX_SOM];

ll calcDist(ll a,ll b) {
    if (a>b) {
        swap(a,b);
    }
    return cumu[b]-cumu[a];
}

ll calcMax(ll deb,ll fin) {
    if (deb==fin) {
        return arbreMax[deb];
    }
    if (deb%2==1) {
        return max(arbreMax[deb],calcMax(deb+1,fin));
    }
    if (fin%2==0) {
        return max(arbreMax[fin],calcMax(deb,fin-1));
    }
    return calcMax(deb/2,fin/2);
}

ll calcInter(ll deb,ll fin) {
    if (deb>=fin) {
        return 0;
    }
    if (memo[deb][fin]!=-1) {
        return memo[deb][fin];
    }
    memo[deb][fin]=max(calcInter(deb+1,fin),calcMax(DECA+deb+1,DECA+fin)+distStat[deb]-cumu[deb]);
    return memo[deb][fin];
}

ll calcDiam(ll deb,ll fin) {
    ll diam=max(calcInter(0,deb),calcInter(fin,nbSom-1));
    ll tempDeb=distStat[deb],tempFin=distStat[fin];
    for (ll i=0;i<deb;i++) {
        distStat[deb]=max(distStat[deb],calcDist(i,deb)+distStat[i]);
    }
    for (ll i=fin+1;i<nbSom;i++) {
        distStat[fin]=max(distStat[fin],calcDist(fin,i)+distStat[i]);
    }
    for (ll a=deb;a<=fin;a++) {
        for (ll b=a+1;b<=fin;b++) {
            diam=max(diam,min(calcDist(a,b),calcDist(a,deb)+calcDist(b,fin)+prixNouv)+distStat[a]+distStat[b]);
        }
    }
    distStat[deb]=tempDeb;
    distStat[fin]=tempFin;
    //cout<<deb<<" "<<fin<<" "<<diam<<endl;
    return diam;
}

ll find_shortcut(int n,vector<int> l,vector<int> d,int c) {
    nbSom=n;
    for (int i=0;i<nbSom;i++) {
        for (int j=0;j<nbSom;j++) {
            memo[i][j]=-1;
        }
    }
    prixNouv=c;
    for (ll i=1;i<nbSom;i++) {
        cumu[i]=cumu[i-1]+l[i-1];
    }
    for (ll i=0;i<nbSom;i++) {
        distStat[i]=d[i];
    }
    for (ll i=0;i<nbSom;i++) {
        arbreMax[DECA+i]=distStat[i]+cumu[i];
    }
    for (ll i=DECA-1;i>0;i--) {
        arbreMax[i]=max(arbreMax[2*i],arbreMax[2*i+1]);
    }
    rep=INFINI;
    for (ll i=0;i<nbSom;i++) {
        for (ll j=i+1;j<nbSom;j++) {
            rep=min(rep,calcDiam(i,j));
        }
    }
    return rep;
}

• 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