Submission #104281

#	Time	Username	Problem	Language	Result	Execution time	Memory
104281		naoai	Rail (IOI14_rail)	C++14	100 / 100	97 ms	888 KiB

rail

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

using namespace std;

const int nmax = 5000;

static int v[nmax + 1];
static int tip[nmax + 1];

int d0[nmax + 1];
pair<int, int> ord[nmax + 1];

set<int> C, D;

bool checkC (int pos, int L, int dL, int ind) {
    set<int>::iterator it = D.upper_bound(max(v[0], pos));

    if (it == D.end())
        return 0;

    if (d0[ind] != *it * 2 - v[0] - pos)
        return 0;
    return 1;
}

bool checkD (int pos, int R, int dR, int ind) {
    set<int>::iterator it = C.lower_bound(pos);
    if (it == C.begin())
        return 0;

    -- it;

    if (dR != pos + v[R] - 2 * (*it))
        return 0;

    set<int>::iterator shp = D.upper_bound(v[0]);
    if (shp == D.end())
        return 0;

    return (d0[ind] == (*shp - v[0]) + (pos - *it) + (*shp - *it));
}

bool checkL (int pos, int dr, int dzero) {
    set<int>::iterator it = D.lower_bound(v[0]);

    if (it == D.end())
        return 0;

    if (dzero != 2 * (*it) - v[0] - pos)
        return 0;
    return 1;
}

void findLocation(int N, int first, int location[], int stype[]) {
    v[0] = first;
    tip[0] = 1;

    for (int i = 1; i < N; ++ i) {
        int x;
        x = getDistance(0, i);
        d0[i] = x;

        ord[i] = {d0[i], i};
    }

    sort(ord + 1, ord + N);
    int l = 0, r = ord[1].second;
    v[r] = v[0] + d0[r];
    tip[r] = 2;

    C.insert(v[0]);
    D.insert(v[r]);

    for (int i = 2; i < N; ++ i) {
        int c = ord[i].second;

        int dl = getDistance(c, l), dr = getDistance(c, r);

        if (v[0] < v[r] - dr && checkC(v[r] - dr, l, dl, c)) {
            tip[c] = 1;
            v[c] = v[r] - dr;
            C.insert(v[c]);
        } else if (v[l] + dl < v[0] && checkD(v[l] + dl, r, dr, c)){
            tip[c] = 2;
            v[c] = v[l] + dl;
            D.insert(v[c]);
        } else if (v[r] - dr < v[l] && checkL(v[r] - dr, dr, d0[c])) {
            tip[c] = 1;
            v[c] = v[r] - dr;
            C.insert(v[c]);
        } else {
            tip[c] = 2;
            v[c] = v[l] + dl;
            D.insert(v[c]);
        }

        if (v[c] > v[r])
            r = c;
        if (v[c] < v[l])
            l = c;
    }

    for (int i = 0; i < N; ++ i) {
        location[i] = v[i];
        stype[i] = tip[i];
    }
}

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