Submission #1080866

#	Time	Username	Problem	Language	Result	Execution time	Memory
1080866		alexdd	Swapping Cities (APIO20_swap)	C++17	0 / 100	95 ms	21684 KiB

swap

#include "swap.h"
#include <bits/stdc++.h>
using namespace std;
const int INF = 2e9;
int father[100005],siz[100005],cap1[100005],cap2[100005],primu[100005],insus[100005],parent[100005];
int gas(int x)
{
    if(father[x]!=x)
        father[x]=gas(father[x]);
    return father[x];
}
void unite(int x, int y, int t)
{
    int rootx = gas(x), rooty = gas(y);
    if(rootx==rooty)
    {
        primu[rootx] = min(primu[rootx], t);
        return;
    }
    if(siz[rootx] < siz[rooty])
    {
        swap(rootx,rooty);
        swap(x,y);
    }
    insus[y]=t;
    father[y]=x;
    parent[y]=x;
    siz[x]+=siz[y];

    if(primu[rootx]!=INF)
    {

    }
    else if(primu[rooty]!=INF)
    {
        primu[rootx]=t;
    }
    else if(x==cap1[rootx] && y==cap1[rooty])
    {
        cap1[rootx]=cap2[rooty];
    }
    else if(x==cap1[rootx] && y==cap2[rooty])
    {
        cap1[rootx]=cap1[rooty];
    }
    else if(x==cap2[rootx] && y==cap1[rooty])
    {
        cap2[rootx]=cap2[rooty];
    }
    else if(x==cap2[rootx] && y==cap2[rooty])
    {
        cap2[rootx]=cap1[rooty];
    }
    else
    {
        primu[rootx]=t;
    }
}

vector<pair<int,pair<int,int>>> edges;
vector<int> con[100005];
int tin[100005],tout[100005],timer;
int depth[100005];
void dfs(int nod)
{
    tin[nod]=++timer;
    for(auto adj:con[nod])
    {
        depth[adj]=depth[nod]+1;
        dfs(adj);
    }
    tout[nod]=++timer;
}
bool isanc(int x, int y)
{
    return (tin[x]<=tin[y] && tout[x]>=tout[y]);
}
void init(int N, int M, std::vector<int> U, std::vector<int> V, std::vector<int> W)
{
    for(int i=0;i<M;i++)
        edges.push_back({W[i],{U[i],V[i]}});
    sort(edges.begin(),edges.end());
    for(int i=0;i<N;i++)
    {
        parent[i]=-1;
        father[i]=i;
        siz[i]=1;
        cap1[i]=cap2[i]=i;
        primu[i]=INF;
    }
    for(int i=0;i<edges.size();i++)
    {
        unite(edges[i].second.first, edges[i].second.second, edges[i].first);
    }
    for(int i=0;i<N;i++)
        if(parent[i]!=-1)
            con[parent[i]].push_back(i);
    for(int i=0;i<N;i++)
        if(parent[i]==-1)
            dfs(i);
}

int getMinimumFuelCapacity(int x, int y)
{
    return -1;
    int mnm=INF,aux=0;
    while(x!=-1 && !isanc(x,y))
    {
        aux = max(aux, insus[x]);
        x = parent[x];
    }
    if(x==-1)
        return -1;
    while(y!=x)
    {
        aux = max(aux, insus[y]);
        y = parent[y];
    }
    while(x!=-1)
    {
        mnm = min(mnm, max(aux, primu[x]));
        aux = max(aux, insus[x]);
        x = parent[x];
    }
    if(mnm==INF)
        return -1;
    else
        return mnm;
}

Compilation message (stderr)

swap.cpp: In function 'void init(int, int, std::vector<int>, std::vector<int>, std::vector<int>)':
swap.cpp:91:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, std::pair<int, int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   91 |     for(int i=0;i<edges.size();i++)
      |                 ~^~~~~~~~~~~~~

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