#175. 【NOIP2020】排水系统

https://sjzezoj.com/submission/64187

S2OJ/175/175.cpp

@@ -0,0 +1,91 @@
+#include <iostream>
+#include <algorithm>
+#include <string>
+#include <utility>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+int n, m, d, t;
+std::vector<int> u[100005];
+std::pair<__int128, __int128> ans[100005];
+
+std::ostream& operator<<(std::ostream& __ostream, __int128 __n) {
+    std::string __o;
+
+    while (__n) {
+        __o.push_back(__n % 10 + '0');
+        __n /= 10;
+    }
+
+    std::reverse(__o.begin(), __o.end());
+
+    return __ostream << __o;
+}
+
+__int128 gcd(__int128 a, __int128 b) {
+    if (b == 0) return a;
+    return gcd(b, a % b);
+}
+
+void dfs(int x, __int128 first, __int128 second) {
+    if (u[x].empty()) {
+        if (ans[x].first && ans[x].second) {
+            if (ans[x].second == second) {
+                ans[x].first += first;
+                __int128 tmp = gcd(ans[x].first, ans[x].second);
+                ans[x].first /= tmp;
+                ans[x].second /= tmp;
+            } else {
+                first *= ans[x].second;
+                ans[x].first *= second;
+                ans[x].first += first;
+                ans[x].second *= second;
+                __int128 tmp = gcd(ans[x].first, ans[x].second);
+                ans[x].first /= tmp;
+                ans[x].second /= tmp;
+            }
+        } else {
+            ans[x].first = first;
+            ans[x].second = second;
+        }
+
+        return;
+    }
+
+    int s = u[x].size();
+    second *= s;
+
+    for (int i = 0; i < s; i++) {
+        dfs(u[x][i], first, second);
+    }
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> m;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> d;
+        for (int j = 1; j <= d; j++) {
+            cin >> t;
+            u[i].emplace_back(t);
+        }
+    }
+
+    for (int i = 1; i <= m; i++) {
+        dfs(i, 1, 1);
+    }
+
+    for (int i = 1; i <= n; i++) {
+        if (u[i].empty()) {
+            cout << ans[i].first << ' ' << ans[i].second << endl;
+        }
+    }
+
+    return 0;
+}