20240604 InHng's submission for CF1949I (Yawn-Sean#3176)

daily_problems/2024/06/0604/personal_submission/cf1949i_inhng.cpp

@@ -0,0 +1,69 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+#define ff first
+#define ss second
+#define endl '\n'
+#define int long long
+#define lowbit(x) x & -x
+#define PII pair<int, int>
+#define PIII pair<int, PII>
+
+const int INF = 0x3f3f3f3f;
+const int mod = 1e9 + 7; // 998244353;
+
+void solve() {
+    int n;
+    cin >> n;
+    vector<array<int, 3>> a(n);
+    vector<int> g[n], color(n, -1);
+    for (array<int, 3> &ai : a) {
+        cin >> ai[0] >> ai[1] >> ai[2];
+    }
+    for (int i = 0; i < n; ++i) {
+        for (int j = i + 1; j < n; ++j) {
+            if (pow(a[i][0] - a[j][0], 2) + pow(a[i][1] - a[j][1], 2) == pow(a[i][2] + a[j][2], 2)) {
+                g[i].emplace_back(j);
+                g[j].emplace_back(i);
+            }
+        }
+    }
+    for (int i = 0; i < n; ++i) {
+        if (color[i] == -1) {
+            color[i] = 0;
+            int cnt = 0;
+            bool ok = true;
+            queue<int> q;
+            q.emplace(i);
+            while (q.size()) {
+                int u = q.front();
+                q.pop();
+                cnt += (color[u] ? -1 : 1);
+                for (int v : g[u]) {
+                    if (color[u] == color[v]) {
+                        ok = false;
+                    } else if (color[v] == -1) {
+                        color[v] = color[u] ^ 1;
+                        q.emplace(v);
+                    }
+                }
+            }
+            if (ok and cnt) {
+                cout << "YES";
+                return;
+            }
+        }
+    }
+    cout << "NO";
+}
+
+signed main() {
+    cin.tie(nullptr)->sync_with_stdio(false);
+    cout << fixed << setprecision(15);
+    time_t begin = clock();
+    solve();
+    time_t end = clock();
+    double solve_time = double(end - begin) / CLOCKS_PER_SEC;
+    // cout << "runtime: " << solve_time << endl;
+    return 0;
+}