Submission #402553

#	Time	Username	Problem	Language	Result	Execution time	Memory
402553		Nnandi	Stations (IOI20_stations)	C++14	100 / 100	1124 ms	712 KiB

stations

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

void dfs(std::vector<std::vector<int> > &graph, std::vector<int> &labels, int p, bool nodeType, int &clock) {
    labels[p] = -1;

    if(nodeType == true) {
        labels[p] = clock;
        clock++;
    }

    for(int q:graph[p]) {
        if(labels[q] == -2) {
            dfs(graph,labels,q,!nodeType,clock);
        }
    }

    if(nodeType == false) {
        labels[p] = clock;
        clock++;
    }

    return;
}

std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v) {

	//graph transformation

	std::vector<std::vector< int > > graph(n);
	for(int i=0;i<n-1;i++) {
        graph[u[i]].push_back(v[i]);
        graph[v[i]].push_back(u[i]);
	}

	std::vector<int> labels(n,-2);

	//labeling process

	bool initNode = true;
	int clock = 0;
	dfs(graph,labels,0,initNode,clock);

	return labels;
}

int find_next_station(int s, int t, std::vector<int> c) {
	//finding out the node type
	std::sort(c.begin(),c.end());

	int degree = c.size();
	int fatherNode;

	if(s < c[0]) {
        //s is labeled by arrival time
        fatherNode = c[degree - 1];
        if(t < s || t > fatherNode) {
            //should be sent to father node
            return fatherNode;
        }
        int dest = -1;
        for(int q:c) {
            if(t <= q && dest == -1) {
                dest = q;
            }
        }
        return dest;
	}
	else {
        //s is labeled by departure time
        std::reverse(c.begin(),c.end());
        fatherNode = c[degree - 1];
        if(t > s || t < fatherNode) {
            //should be sent to father node
            return fatherNode;
        }
        int dest = -1;
        for(int q:c) {
            if(t >= q && dest == -1) {
                dest = q;
            }
        }
        return dest;

	}
}

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 16 / 16
• Subtask 4: 10 / 10
• Subtask 5: 61 / 61