Submission #916372

#	Time	Username	Problem	Language	Result	Execution time	Memory
916372		biank	Rail (IOI14_rail)	C++14	30 / 100	47 ms	888 KiB

rail

#include "rail.h"
#include <bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define forn(i,n) for(int i=0;i<int(n);i++)
#define forsn(i,s,n) for(int i=int(s);i<int(n);i++)
#define fst first
#define snd second
typedef pair<int,int> ii;

const int C = 1, D = 2;

void findLocation(int n, int first, int loc[], int stype[]) {
    vector<ii> p(n);
    forsn(i,1,n) p[i]={getDistance(0,i),i};
    sort(ALL(p));
    set<ii> Cs, Ds;
    for(auto [d0,i]:p) {
        if(Cs.empty()) {
            loc[i]=first;
            stype[i]=C;
            Cs.insert((ii){loc[i],i});
            continue;
        }
        int minC = Cs.begin()->snd;
        if(Ds.empty()) {
            loc[i]=loc[minC]+d0;
            stype[i]=D;
            Ds.insert((ii){loc[i],i});
            continue;
        }
        int maxD = Ds.rbegin()->snd;
        int distItoC = getDistance(i,minC);
        int distItoD = getDistance(maxD,i);
        loc[i] = loc[minC] + distItoC;
        int target = (loc[i] + loc[maxD] - distItoD)/2;
        auto it = Cs.lower_bound((ii){target,0});
        if(it != Cs.end() && loc[i] - it->fst + loc[maxD] - it->fst == distItoD) {
            stype[i] = D;
            Ds.insert((ii){loc[i],i});
            continue;
        }
        loc[i] = loc[maxD] - distItoD;
        target = (distItoC + loc[i] + loc[minC])/2;
        it = Ds.lower_bound((ii){target,0});
        if(it != Ds.end() && it->fst - loc[i] + it->fst - loc[minC] == distItoC) {
            stype[i] = C;
            Cs.insert((ii){loc[i],i});
            continue;
        }
        assert(false);
    }
}

Compilation message (stderr)

rail.cpp: In function 'void findLocation(int, int, int*, int*)':
rail.cpp:18:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   18 |     for(auto [d0,i]:p) {
      |              ^

• Subtask 1: 8 / 8
• Subtask 2: 22 / 22
• Subtask 3: 0 / 26
• Subtask 4: 0 / 44