Submission #878587

#	Time	Username	Problem	Language	Result	Execution time	Memory
878587		MasterTaster	Paths (BOI18_paths)	C++14	70 / 100	559 ms	193516 KiB

paths

#include <bits/stdc++.h>

#define ll long long
#define pii pair<int, int>
#define xx first
#define yy second
#define pb push_back
#define MAXN 300010
#define MAXK 8

using namespace std;

int n, m, k, a[MAXN];
ll cnt[MAXN][MAXK], ress, cntt[MAXN][MAXK][MAXK];
vector<pii> grane;
vector<int> g[MAXN];

int main() {
    cin>>n>>m>>k;

    for (int i=1; i<=n; i++)
        cin>>a[i];

    for (int i=0; i<m; i++)
    {
        int u, v; cin>>u>>v;
        grane.pb({u, v});
        g[u].pb(v); g[v].pb(u);
        cnt[u][a[v]]++;
        cnt[v][a[u]]++;
    }

    for (auto par:grane)
    {
        int u=par.xx, v=par.yy;
        if (a[u]==a[v]) continue;
        ress+=2;
        vector<int> boje;
        for (int i=1; i<=5; i++) if (a[u]!=i && a[v]!=i) boje.pb(i);
        int c1, c2, c3;
        c1=boje[0]; c2=boje[1]; c3=boje[2];
        ress+=2*((cnt[u][c1]*cnt[v][c2])+(cnt[u][c2]*cnt[v][c1]) + (cnt[u][c1]*cnt[v][c3])+(cnt[u][c3]*cnt[v][c1]) + (cnt[u][c3]*cnt[v][c2])+(cnt[u][c2]*cnt[v][c3]))
                +cnt[u][c1]+cnt[u][c2]+cnt[u][c3]+cnt[v][c1]+cnt[v][c2]+cnt[v][c3];
        //cout<<u<<" "<<v<<" "<<ress<<endl;
    }

    for (int u=1; u<=n; u++)
    {
        for (auto v:g[u])
        {
            if (a[u]==a[v]) continue;
            vector<int> boje;
            for (int i=1; i<=5; i++)
                if (a[u]!=i && a[v]!=i) boje.pb(i);
            for (auto c:boje)
                cntt[u][a[v]][c]+=cnt[v][c];
        }
    }

    ll press=0;
    for (int u=1; u<=n; u++)
    {
        vector<int> boje;
        for (int i=1; i<=5; i++) if (a[u]!=i) boje.pb(i);

        for (int i=0; i<boje.size(); i++)
        {
            for (int j=0; j<boje.size(); j++)
            {
                if (i==j) continue;
                int c1=boje[i], c2=boje[j], c3=-1, c4=-1;
                for (int k=0; k<boje.size(); k++) { if (k!=i && k!=j) { if (c3==-1) c3=boje[k]; else c4=boje[k]; } }
                press+=(cntt[u][c1][c2]*cntt[u][c3][c4]+cntt[u][c1][c2]*cntt[u][c4][c3]);
                //cout<<u<<" "<<" "<<c1<<" "<<c2<<" "<<c3<<" "<<c4<<": "<<press<<endl;

            }
        }
    }
    if (press%2==1) assert(0);
    press/=2;
    ress+=press;
    //cout<<press<<endl;
    cout<<ress;
}
/*
8 7 5
1 2 3 1 4 5 5 4
1 2
2 3
3 4
2 5
5 6
2 7
7 8
 */

Compilation message (stderr)

paths.cpp: In function 'int main()':
paths.cpp:66:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   66 |         for (int i=0; i<boje.size(); i++)
      |                       ~^~~~~~~~~~~~
paths.cpp:68:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |             for (int j=0; j<boje.size(); j++)
      |                           ~^~~~~~~~~~~~
paths.cpp:72:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |                 for (int k=0; k<boje.size(); k++) { if (k!=i && k!=j) { if (c3==-1) c3=boje[k]; else c4=boje[k]; } }
      |                               ~^~~~~~~~~~~~

• Subtask 1: 23 / 23
• Subtask 2: 20 / 20
• Subtask 3: 27 / 27
• Subtask 4: 0 / 30