SkyNet Revolution - Episode 2

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

/**
 * Auto-generated code below aims at helping you parse
 * the standard input according to the problem statement.
 **/

int nodes1[500];
int nodes2[500];
int gateways[20];

int nodesgateway1[500];
int nodesgateway2[500];

int nodesneargateway1[500];
int nodesneargateway2[500];

int main()
{

    for (int i; i < 500; i++)
    {
        nodes1[i] = -100;
        nodes2[i] = -100;

        nodesgateway1[500] = -100;
        nodesgateway2[500] = -100;

        nodesneargateway1[500] = -100;
        nodesneargateway2[500] = -100;
    }

    for (int i; i < 20; i++)
    {
        gateways[i] = -100;
    }

    int N; // the total number of nodes in the level, including the gateways
    int L; // the number of links
    int E; // the number of exit gateways
    cin >> N >> L >> E; cin.ignore();
    for (int i = 0; i < L; i++) {
        int N1; // N1 and N2 defines a link between these nodes
        int N2;
        cin >> N1 >> N2; cin.ignore();
        nodes1[i] = N1;
        nodes2[i] = N2;
    }
    for (int i = 0; i < E; i++) {
        int EI; // the index of a gateway node
        cin >> EI; cin.ignore();
    }

    // game loop
    while (1) {
        int SI; // The index of the node on which the Skynet agent is positioned this turn
        cin >> SI; cin.ignore();

        for (int i; i < 500; i++)
        {
            if (nodes1[i] != -100 && nodes2[i] != -100)
            {
                for (int i2; i2 < 20; i2++)
                {
                    if (nodes1[i] == gateways[i2] || nodes2[i] == gateways[i2])
                    {
                        nodesgateway1[i] = nodes1[i];
                        nodesgateway2[i] = nodes2[i];
                    }
                }
            }
        }

        for (int i; i < 500; i++)
        {
            if (nodes1[i] != -100 && nodes2[i] != -100)
            {
                if (nodes1[i] == nodesgateway1[i] || nodes2[i] == nodesgateway2[i] || nodes2[i] == nodesgateway1[i] || nodes1[i] == nodesgateway2[i])
                {
                    nodesneargateway1[i] = nodes1[i];
                    nodesneargateway2[i] = nodes2[i];
                }
            }
        }


        for (int i; i < 500; i++)
        {
            if (nodesgateway1[i] == SI || nodesgateway2[i] == SI) cout<<nodesgateway1[i]<<" "<<nodesgateway2[i]<<endl;
            else
            {
                if (nodesneargateway1[i] == SI || nodesneargateway2[i] == SI)
                {
                    for (int i2; i2 < 500; i2++)
                    {
                        if (nodesgateway2[i2] == nodesneargateway1[i] || nodesgateway1[i2] == nodesneargateway2[i] || nodesgateway1[i2] == nodesneargateway1[i] || nodesgateway2[i2] == nodesneargateway2[i])
                        {
                            cout<<nodesgateway1[i2]<<" "<<nodesgateway2[i2]<<endl;
                        }
                    }
                }
            }
        }
    }
}