Submission #1078462

#	Time	Username	Problem	Language	Result	Execution time	Memory
1078462		alexdd	Swapping Cities (APIO20_swap)	C++17	0 / 100	411 ms	524288 KiB

swap

#include "swap.h"
#include <bits/stdc++.h>
using namespace std;
const int BUC = 500;
const int CNTB = 400;
const int MAXN = 100000;

struct str_DSU
{
    int father[MAXN+5],siz[MAXN+5],cap1[MAXN+5],cap2[MAXN+5],islant[MAXN+5];
    vector<pair<int*,int>> history;
    void init(int N)
    {
        for(int i=0;i<N;i++)
        {
            siz[i]=1;
            father[i]=cap1[i]=cap2[i]=i;
            islant[i]=1;
        }
    }
    int gas(int x)
    {
        if(father[x]==x)
            return x;
        return gas(father[x]);
    }
    void unite(int x, int y)
    {
        int rootx = gas(x);
        int rooty = gas(y);
        if(rootx==rooty)
        {
            if(islant[rootx])
            {
                history.push_back({&islant[rootx],islant[rootx]});
                islant[rootx]=0;
            }
            return;
        }
        if(siz[rootx] < siz[rooty])
        {
            swap(rootx,rooty);
            swap(x,y);
        }

        history.push_back({&father[y],father[y]});
        history.push_back({&siz[x],siz[x]});
        father[y]=x;
        siz[x]+=siz[y];

        if(!islant[rootx] || !islant[rooty])
        {
            if(islant[rootx])
            {
                history.push_back({&islant[rootx],islant[rootx]});
                islant[rootx]=0;
            }
        }
        else if(x==cap1[rootx] && y==cap1[rooty])
        {
            history.push_back({&cap1[rootx],cap1[rootx]});
            cap1[rootx] = cap2[rooty];
        }
        else if(x==cap1[rootx] && y==cap2[rooty])
        {
            history.push_back({&cap1[rootx],cap1[rootx]});
            cap1[rootx] = cap1[rooty];
        }
        else if(x==cap2[rootx] && y==cap1[rooty])
        {
            history.push_back({&cap2[rootx],cap2[rootx]});
            cap2[rootx] = cap2[rooty];
        }
        else if(x==cap2[rootx] && y==cap2[rooty])
        {
            history.push_back({&cap2[rootx],cap2[rootx]});
            cap2[rootx] = cap1[rooty];
        }
        else
        {
            history.push_back({&islant[rootx],islant[rootx]});
            islant[rootx]=0;
        }
    }
    void rollback(int t)
    {
        while((int)history.size() > t)
        {
            *history.back().first = history.back().second;
            history.pop_back();
        }
    }
};

vector<str_DSU> saves;
vector<int> pozs;

str_DSU dsu;
void do_save(int i, int N)
{
    //cout<<i<<" save\n";
    pozs.push_back(i);
    saves.push_back(dsu);
}
vector<pair<int,pair<int,int>>> edges;
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());
    dsu.init(N);
    do_save(-1,N);
    for(int i=0;i<M;i++)
    {
        dsu.unite(edges[i].second.first, edges[i].second.second);
        if((i+1)%BUC==0 || i==M-1)
        {
            do_save(i,N);
        }
    }
}

int getMinimumFuelCapacity(int X, int Y)
{
    int ults=0;
    for(int i=1;i<saves.size();i++)
    {
        if(saves[i].gas(X)==saves[i].gas(Y) && saves[i].islant[saves[i].gas(X)]==0)
            break;
        ults=i;
    }
    if(ults==(int)saves.size()-1)
        return -1;
    //str_DSU cop = saves[ults];///-------------------------
    int t = saves[ults].history.size();
    for(int i=pozs[ults]+1;i<edges.size();i++)
    {
        int a = edges[i].second.first, b = edges[i].second.second;
        //cout<<a<<" "<<b<<" baga\n";
        saves[ults].unite(a, b);
        if(saves[ults].gas(X)==saves[ults].gas(Y) && saves[ults].islant[saves[ults].gas(X)]==0)
        {
            saves[ults].rollback(t);
            //saves[ults] = cop;///--------------------------
            return edges[i].first;
            break;
        }
    }
    assert(1==0);
}

Compilation message (stderr)

swap.cpp: In function 'int getMinimumFuelCapacity(int, int)':
swap.cpp:125:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<str_DSU>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  125 |     for(int i=1;i<saves.size();i++)
      |                 ~^~~~~~~~~~~~~
swap.cpp:135:29: 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]
  135 |     for(int i=pozs[ults]+1;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