Submission #683364

#	Time	Username	Problem	Language	Result	Execution time	Memory
683364		nifeshe	Star triangles (IZhO11_triangle)	C++14	100 / 100	288 ms	15580 KiB

triangle

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

//#pragma GCC target ("avx2")
//#pragma GCC optimize ("O3")
//#pragma GCC optimize ("unroll-loops")
//#pragma comment (linker, "/STACK: 16777216")

#define f first
#define s second
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) (x).size()
#define pb push_back
#define mp make_pair
#define int long long

using namespace std;
using namespace __gnu_pbds;

template <typename T> inline bool umax(T &a, const T &b) { if(a < b) { a = b; return 1; } return 0; }
template <typename T> inline bool umin(T &a, const T &b) { if(a > b) { a = b; return 1; } return 0; }
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
template <typename T> using oset = tree<T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;

const ll mod = 998244353;
const ll base = 1e6 + 5;
const ll inf = 1e18;
const int MAX = 2000;
const int lg = 20;

random_device rd;
mt19937 gen(rd());
uniform_int_distribution<ll> dis(1, inf);

void solve() {
    int n;
    cin >> n;
    vector<int> x(n), y(n);
    map<int, int> cntx, cnty;
    for(int i = 0; i < n; i++) {
        cin >> x[i] >> y[i];
        cntx[x[i]]++; cnty[y[i]]++;
    }
    int ans = 0;
    for(int i = 0; i < n; i++) {
        ans += (cntx[x[i]] - 1) * (cnty[y[i]] - 1);
    }
    cout << ans << '\n';
}

signed main() {
    //freopen("triangles.in", "r", stdin); freopen("triangles.out", "w", stdout);
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int ttt = 1;
//    cin >> ttt;
    while(ttt--) {
        solve();
    }
    return 0;
}

• Subtask 1: 100 / 100