Submission #579582

#	Time	Username	Problem	Language	Result	Execution time	Memory
579582		elazarkoren	Rail (IOI14_rail)	C++17	30 / 100	83 ms	524 KiB

rail

#include "rail.h"
#include <bits/stdc++.h>
#define x first
#define y second
#define all(v) v.begin(), v.end()
#define chkmin(a, b) a = min(a, b)
#define chkmax(a, b) a = max(a, b)
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vii;

const int MAX_N = 5005;

int dist0[MAX_N], dist1[MAX_N];

void findLocation(int n, int first, int location[], int stype[]) {
    int closest = 1;
    for (int i = 1; i < n; i++) {
        dist0[i] = getDistance(0, i);
        if (dist0[i] < dist0[closest]) closest = i;
    }
    location[0] = first, stype[0] = 1;
    location[closest] = dist0[closest] + first, stype[closest] = 2;
    vi ind_l, ind_r;
    dist1[0] = dist0[closest];
    for (int i = 1; i < n; i++) {
        if (i == closest) continue;
        dist1[i] = getDistance(closest, i);
        if (dist0[i] != dist0[closest] + dist1[i]) {
            ind_r.push_back(i);
        } else if (dist1[i] > dist1[0]) {
            ind_l.push_back(i);
        } else {
            location[i] = location[closest] - dist1[i];
            stype[i] = 1;
        }
    }
    if (!ind_r.empty()) {
        sort(all(ind_r), [&](int i, int j) {
            return dist0[i] < dist0[j];
        });
        int last = ind_r[0];
        location[last] = first + dist0[last];
        stype[last] = 2;
        vi v = {last};
        for (int i : ind_r) {
            if (i == last) continue;
            int d = getDistance(last, i);
            int x1 = location[last] - d;
            int j;
            for (int k : v) {
                if (location[k] > x1) {
                    j = k;
                    break;
                }
            }
            if (location[last] - (dist0[last] + d - dist0[i]) != location[j]) {
//            if (getDistance(j, i) + dist0[j] != dist0[i]) {
                stype[i] = 2;
                location[i] = dist0[i] + first;
                last = i;
                v.push_back(i);
            } else {
                stype[i] = 1;
                location[i] = first + 2 * dist0[j] - dist0[i];
            }
        }
    }
    if (!ind_l.empty()) {
        sort(all(ind_l), [&](int i, int j) {
            return dist1[i] < dist1[j];
        });
        int last = ind_l[0];
        location[last] = location[closest] - dist1[last];
        stype[last] = 1;
        vi v = {last};
        for (int i : ind_l) {
            if (i == last) continue;
            int d = getDistance(last, i);
            int x1 = location[last] + d;
            int j;
            for (int k : v) {
                if (location[k] < x1) {
                    j = k;
                    break;
                }
            }
            if (location[last] + (dist1[last] + d - dist1[i]) != location[j]) {
//            if (getDistance(j, i) + dist1[j] != dist1[i]) {
                stype[i] = 1;
                location[i] = location[closest] - dist1[i];
                last = i;
                v.push_back(i);
            } else {
                stype[i] = 2;
                location[i] = location[closest] - (2 * dist1[j] - dist1[i]);
            }
        }
    }
}

Compilation message (stderr)

rail.cpp: In function 'void findLocation(int, int, int*, int*)':
rail.cpp:91:75: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized]
   91 |             if (location[last] + (dist1[last] + d - dist1[i]) != location[j]) {
      |                                                                           ^
rail.cpp:60:75: warning: 'j' may be used uninitialized in this function [-Wmaybe-uninitialized]
   60 |             if (location[last] - (dist0[last] + d - dist0[i]) != location[j]) {
      |                                                                           ^

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