Submission #429583

#	Time	Username	Problem	Language	Result	Execution time	Memory
429583		snasibov05	Swapping Cities (APIO20_swap)	C++14	13 / 100	395 ms	34044 KiB

swap

#include "swap.h"
#include <vector>
#include <algorithm>

using namespace std;

#define pii pair<int, int>
#define f first
#define s second
#define pb push_back
#define oo 1000000001

struct edge{
    int u, v;
    int cost;

    bool operator< (edge e) const{
        return cost < e.cost;
    }
};


vector<int> pr;
vector<edge> ed;
vector<int> deg;
vector<vector<int>> cmp;
vector<vector<pii>> arr;
vector<int> when;

void Union(edge e){
    deg[e.u]++; deg[e.v]++;

    int x = pr[e.u];
    int y = pr[e.v];

    if (x == y){
        when[x] = min(when[x], e.cost);
        return;
    }

    if (cmp[x].size() < cmp[y].size()) swap(x, y);

    for (auto node : cmp[y]){
        cmp[x].pb(node);
        pr[node] = x;
        arr[node].pb({x, e.cost});
    }
    cmp[y].clear();
    when[x] = min(when[x], when[y]);
    if (deg[e.u] >= 3 || deg[e.v] >= 3) when[x] = min(when[x], e.cost);
}

void init(int n, int m, vector<int> u, vector<int> v, vector<int> w) {
    pr.resize(n);
    ed.resize(m);
    deg.resize(n);
    cmp.resize(n);
    arr.resize(n);
    when.resize(n);

    for (int i = 0; i < m; ++i) {
        ed[i].u = u[i];
        ed[i].v = v[i];
        ed[i].cost = w[i];
    }

    for (int i = 0; i < n; ++i) {
        pr[i] = i;
        cmp[i].pb(i);
        deg[i] = 0;
        arr[i].pb({i, 0});
        when[i] = oo;
    }


    sort(ed.begin(), ed.end());

    for (int i = 0; i < m; ++i) {
        Union(ed[i]);
    }

}

int getMinimumFuelCapacity(int x, int y) {

    int ans = 0;
    if (when[pr[x]] == oo) return -1;
    int cmpx = x, cmpy = y;
    int a = 0, b = 0;

    while (cmpx != cmpy || when[cmpx] == oo){
        if (a == arr[x].size()){
            cmpy = arr[y][b].f;
            ans = max(ans, arr[y][b++].s);
        } else if (b == arr[y].size()){
            cmpx = arr[x][a].f;
            ans = max(ans, arr[x][a++].s);
        } else if (arr[x][a].s < arr[y][b].s){
            cmpx = arr[x][a].f;
            ans = max(ans, arr[x][a++].s);
        } else{
            cmpy = arr[y][b].f;
            ans = max(ans, arr[y][b++].s);
        }
    }

    ans = max(ans, when[cmpx]);

    return ans;
}

Compilation message (stderr)

swap.cpp: In function 'int getMinimumFuelCapacity(int, int)':
swap.cpp:92:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   92 |         if (a == arr[x].size()){
      |             ~~^~~~~~~~~~~~~~~~
swap.cpp:95:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   95 |         } else if (b == arr[y].size()){
      |                    ~~^~~~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 0 / 17
• Subtask 4: 0 / 20
• Subtask 5: 0 / 23
• Subtask 6: 0 / 27