Submission #829711

#	Time	Username	Problem	Language	Result	Execution time	Memory
829711		Abrar_Al_Samit	Fountain Parks (IOI21_parks)	C++17	30 / 100	777 ms	47400 KiB

parks

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

const int nax = 200000;
vector<int>g[nax];
bool vis[nax];
int par[nax], sz[nax];

void trav(int v) {
    vis[v] = 1;
    for(int u : g[v]) if(!vis[u]) {
        trav(u);
    }
}

int find(int v) {
    return par[v] = (v==par[v]) ? v : find(par[v]);
}
void unite(int u, int v) {
    u = find(u), v = find(v);
    if(sz[u] < sz[v]) swap(u, v);
    sz[u] += sz[v];
    par[v] = u;
}
int construct_roads(vector<int> x, vector<int> y) {
    int n = x.size();
    map<pair<int,int>, int>ft;
    for(int i=0; i<n; ++i) {
        ft[{x[i], y[i]}] = i;
    }

    int dx[] = {2, -2, 0, 0};
    int dy[] = {0, 0, 2, -2};

    vector<int>u, v, a, b;

    map<pair<int,int>, int>ben;

    for(int i=0; i<n; ++i) {
        par[i] = i, sz[i] = 1;
    }
    for(int i=0; i<n; ++i) {
        for(int j=2; j<4; ++j) {
            int nx = x[i] + dx[j], ny = y[i] + dy[j];
            if(ft.count(make_pair(nx, ny))) {
                if(find(i) == find(ft[{nx, ny}])) continue;



                if(x[i]==2) {
                    a.push_back(x[i] - 1);
                    b.push_back(y[i] + ny >> 1);
                } else if(x[i]==6) {
                    a.push_back(x[i] + 1);
                    b.push_back(y[i] + ny >> 1);
                } else {
                    if((y[i]+ny)%8<4) {
                        a.push_back(x[i]-1);
                        b.push_back(y[i] + ny >> 1);
                        ben[{x[i]-1, y[i] + ny >> 1}] = 1;
                    } else {
                        a.push_back(x[i]+1);
                        b.push_back(y[i] + ny >> 1);
                        ben[{x[i]+1, y[i] + ny >> 1}] = 1;
                    }
                }
                g[i].push_back(ft[{nx, ny}]);
                g[ft[{nx, ny}]].push_back(i);
                unite(i, ft[{nx, ny}]);
                u.push_back(i);
                v.push_back(ft[{nx, ny}]);
            }
        }
    }

    for(int i=0; i<n; ++i) {
        if(ft.count(make_pair(x[i]+dx[0], y[i]))
            + ft.count(make_pair(x[i]+dx[1], y[i]))==1) {
            for(int j=0; j<2; ++j) {
                int nx = x[i] + dx[j], ny = y[i] + dy[j];
                if(!ft.count(make_pair(nx, ny))) continue;

                int she = ft[{nx, ny}];
                if(find(i) == find(she)) continue;

                g[i].push_back(she);
                g[she].push_back(i);
                unite(i, she);
                u.push_back(i);
                v.push_back(she);

                if(!ben.count(make_pair(x[i] + nx >> 1, ny - 1))) {
                    ben[{x[i] + nx >> 1, ny - 1}] = 1;
                    a.push_back(x[i] + nx >> 1);
                    b.push_back(ny - 1);
                } else if(!ben.count(make_pair(x[i] + nx >> 1, ny + 1))) {
                    ben[{x[i] + nx >> 1, ny + 1}] = 1;
                    a.push_back(x[i] + nx >> 1);
                    b.push_back(ny + 1);

                } else return 0;
            }
        }
    }
    trav(0);
    for(int i=0; i<n; ++i) if(!vis[i]) {
        return 0;
    }

    build(u, v, a, b);
    return 1;
}

Compilation message (stderr)

parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:53:38: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   53 |                     b.push_back(y[i] + ny >> 1);
parks.cpp:56:38: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   56 |                     b.push_back(y[i] + ny >> 1);
parks.cpp:60:42: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   60 |                         b.push_back(y[i] + ny >> 1);
parks.cpp:61:43: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   61 |                         ben[{x[i]-1, y[i] + ny >> 1}] = 1;
parks.cpp:64:42: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   64 |                         b.push_back(y[i] + ny >> 1);
parks.cpp:65:43: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   65 |                         ben[{x[i]+1, y[i] + ny >> 1}] = 1;
parks.cpp:93:46: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   93 |                 if(!ben.count(make_pair(x[i] + nx >> 1, ny - 1))) {
parks.cpp:94:31: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   94 |                     ben[{x[i] + nx >> 1, ny - 1}] = 1;
parks.cpp:95:38: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   95 |                     a.push_back(x[i] + nx >> 1);
parks.cpp:97:53: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   97 |                 } else if(!ben.count(make_pair(x[i] + nx >> 1, ny + 1))) {
parks.cpp:98:31: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   98 |                     ben[{x[i] + nx >> 1, ny + 1}] = 1;
parks.cpp:99:38: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   99 |                     a.push_back(x[i] + nx >> 1);

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 0 / 20
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30