Submission #1095303

#	Time	Username	Problem	Language	Result	Execution time	Memory
1095303		andrewp	Paths (BOI18_paths)	C++14	70 / 100	237 ms	45904 KiB

paths

//Dedicated to my love, ivaziva
#pragma GCC optimize("Ofast") 
#include <bits/stdc++.h> 
using namespace std;  

#define int long long 
 
using pii = pair<int, int>;
using ll = int64_t; 
 
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define dbg(x) cerr<<#x<<": "<<x<<'\n';  
#define dbga(A,l_,r_){for(int i_=l_;i_<=r_;i_++)cerr<<A[i_]<<' ';cerr<<'\n';}
#define dbgv(a_){for(auto x_:a_) cerr<<x_<<' ';cerr<<'\n';}   

const int N = 3e5 + 20;
int n, m, k, a[N], ans;
vector<int> g[N];
int32_t main()  {
    ios::sync_with_stdio(false); cin.tie(nullptr);  
    cout.tie(nullptr); cerr.tie(nullptr);

    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;
        g[u].push_back(v);
        g[v].push_back(u);
    } 
    ans = 0;
    if (k >= 2) {
        for (int i = 1; i <= n; i++) {
            for (int u : g[i]) {
                if (a[u] != a[i]) {
                    ans++;
                }
            }
        }
    }
    if (k >= 3) {
        for (int i = 1; i <= n; i++) {
            vector<int> cnt(k + 1, 0);
            for (int u : g[i]) {
                cnt[a[u]]++;
            }
            for (int x = 1; x <= k; x++) {
                for (int y = 1; y <= k; y++) {
                    if (x != y && x != a[i] && y != a[i]) {
                        ans += cnt[x] * cnt[y];
                    }
                }
            }
        }
    } 
    dbg(ans);
    if (k >= 4) {
        vector<vector<int>> cnt(n + 1, vector<int>(k + 1, 0));
        for (int i = 1; i <= n; i++) {
            for (int u : g[i]) {
                cnt[i][a[u]]++;
            }
        }
        for (int i = 1; i <= n; i++) {
            for (int u : g[i]) {     
                int uk = 0;     
                for (int x = 1; x <= k; x++) {
                    for (int y = 1; y <= k; y++) {
                        if (x != y && a[i] != a[u] && x != a[i] && x != a[u] && y != a[i] && y != a[u]) { 
                            ans += cnt[i][x] * cnt[u][y];                
                        }
                    }
                }    
            }
        }
    } 
    cout << ans << '\n';
    return 0;
}

Compilation message (stderr)

paths.cpp: In function 'int32_t main()':
paths.cpp:69:21: warning: unused variable 'uk' [-Wunused-variable]
   69 |                 int uk = 0;
      |                     ^~

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