Submission #1065251

#	Time	Username	Problem	Language	Result	Execution time	Memory
1065251		Muhammet	Swapping Cities (APIO20_swap)	C++17	100 / 100	267 ms	102844 KiB

swap

#include <bits/stdc++.h>
#include "swap.h"
using namespace std;

#define ll long long
#define sz(s) (int)s.size()
#define ff first
#define ss second

const int N = 400005;

vector <pair<int,pair<int,int>>> v;

int p[N], sp[N][40], p1[N], depth[N], cnt = 0, com[N];

pair <int,int> c[N], d[N];

vector <int> v1[N], v2[N];

int f(int z){
    for(int i = 20; i >= 0; i--){
        if(sp[z][i] != -1 and c[sp[z][i]].ff != 1){
            z = sp[z][i];
        }
    }
    if(c[z].ff == 1) return c[z].ss;
    if(sp[z][0] == -1) return -1;
    z = sp[z][0];
    return c[z].ss;
}

void dfs(int x, int y){
    com[x] = cnt;
    for(auto i : v2[x]){
        if(i != y){
            depth[i] = depth[x]+1;
            dfs(i,x);
        }
    }
}

int fnd(int x){
    if(x == p[x]) return x;
    return p[x] = fnd(p[x]);
}

int lca(int x, int y){
    if(depth[x] < depth[y]) swap(x,y);
    for(int i = 20; i >= 0; i--){
        if(depth[x] - (1<<i) >= depth[y] and sp[x][i] != -1){
            x = sp[x][i];
        }
    }
    for(int i = 20; i >= 0; i--){
        if(sp[x][i] != sp[y][i]){
            x = sp[x][i];
            y = sp[y][i];
        }
    }
    if(sp[x][0] == -1 or sp[x][0] != sp[y][0]) return -1;
    return sp[x][0];
}

void init(int n, int m, vector<int> u1, vector<int> v1, vector<int> w1) {
    for(int i = 0; i < m; i++){
        v.push_back({w1[i],{u1[i],v1[i]}});
    }
    sort(v.begin(), v.end());

    for(int i = 0; i <= n+m; i++){
        p[i] = i;
        c[i] = {0,0};
        d[i] = {i,i};
        p1[i] = i;
    }

    int cn = n-1;
    for(int i = 0; i < sz(v); i++){
        auto x = v[i].ss;
        int a = fnd(p[x.ff]), b = fnd(p[x.ss]);
        cn++;
        // cout << a << ' ' << b << ' ' << cn << ' ';
        if(c[a].ff + c[b].ff == 2 and a == b){
            v2[cn].push_back(a);
            p[a] = cn;
            p1[a] = cn;
            c[cn] = c[a];
        }
        else if(c[a].ff + c[b].ff != 0){
            p[a] = cn;
            p1[a] = cn;
            p[b] = cn;
            p1[b] = cn;
            c[cn] = {1,v[i].ff};
            v2[cn].push_back(a);
            if(a != b) v2[cn].push_back(b);
        }
        else {
            if(a == b){
                c[cn] = {1,v[i].ff};
                p[a] = cn;
                p1[a] = cn;
                v2[cn].push_back(a);
            }
            else {
                v2[cn].push_back(a);
                v2[cn].push_back(b);
                p[a] = cn;
                p1[a] = cn;
                p[b] = cn;
                p1[b] = cn;
                bool tr1 = (d[a].ff == x.ff or d[a].ff == x.ss), tr11 = (d[a].ss == x.ff or d[a].ss == x.ss);
                bool tr2 = (d[b].ff == x.ff or d[b].ff == x.ss), tr22 = (d[b].ss == x.ff or d[b].ss == x.ss);
                if((tr1+tr11) >= 1 and (tr2+tr22) >= 1){
                    c[cn] = {0,v[i].ff};
                    if(tr1 == 1) d[cn] .ff = d[a].ss;
                    else d[cn].ff = d[a].ff;
                    if(tr2 == 1) d[cn].ss = d[b].ss;
                    else d[cn].ss = d[b].ff;
                }
                else {                    
                    c[cn] = {1,v[i].ff};
                }
            }
        }
        // cout << c[cn].ff << ' ' << c[cn].ss << '\n';
    }
    for(int i = cn; i >= 0; i--){
        if(depth[i] == 0){  
            cnt++;
            dfs(i,-1);
        }
    }
    for(int i = 0; i <= cn; i++){
        sp[i][0] = p1[i];
        if(p1[i] == i) sp[i][0] = -1;
    }
    for(int j = 1; j <= 20; j++){
        for(int i = 0; i <= cn; i++){
            if((1<<j) > depth[i]){
                sp[i][j] = -1;
                continue;
            }
            if(sp[i][j-1] != -1){
                sp[i][j] = (sp[sp[i][j-1]][j-1]);
            }
        }
    }
}

int getMinimumFuelCapacity(int x, int y) {
    if(com[x] != com[y]) return -1;
    int z = lca(x,y);
    if(z == -1) return z;
    // cout << z << '\n';
    return f(z);
}

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