'commit'

TangDou/Topic/HuanGenDp/SubTree.cpp

@@ -4,44 +4,49 @@ using namespace std;
 #define endl "\n"
 const int N = 100010;
 
-int n, m;
+int n, mod;
 
 vector<int> s[N];
-int dp[N], pd[N];
+int f[N], g[N];
 
 void dfs1(int x, int fa) {
-    for (int i : s[x]) {
-        if (i != fa) {
-            dfs1(i, x);
-            dp[x] = dp[x] * (dp[i] + 1) % m;
-        }
+    for (int v : s[x]) {
+        if (v == fa) continue;
+        dfs1(v, x);
+        f[x] = f[x] * (f[v] + 1) % mod;
     }
 }
 
 void dfs2(int x, int fa) {
-    int t = pd[x];
-    for (int i : s[x])
-        if (i != fa)
-            pd[i] = pd[i] * t % m;
+    int t = g[x];
+    for (int v : s[x]) {
+        if (v == fa) continue;
+        g[v] = g[v] * t % mod;
+    }
+
     t = 1;
-    for (int i : s[x])
-        if (i != fa)
-            pd[i] = pd[i] * t % m, t = t * (dp[i] + 1) % m;
+    for (int v : s[x]) {
+        if (v == fa) continue;
+        g[v] = g[v] * t % mod, t = t * (f[v] + 1) % mod;
+    }
+
     t = 1;
     reverse(s[x].begin(), s[x].end());
-    for (int i : s[x])
-        if (i != fa)
-            pd[i] = pd[i] * t % m, t = t * (dp[i] + 1) % m;
-    for (int i : s[x])
-        if (i != fa) {
-            ++pd[i];
-            dfs2(i, x);
-        }
+    for (int v : s[x]) {
+        if (v == fa) continue;
+        g[v] = g[v] * t % mod, t = t * (f[v] + 1) % mod;
+    }
+
+    for (int v : s[x]) {
+        if (v == fa) continue;
+        g[v]++;
+        dfs2(v, x);
+    }
 }
 
 signed main() {
-    cin >> n >> m;
-    for (int i = 1; i <= n; i++) dp[i] = pd[i] = 1;
+    cin >> n >> mod;
+    for (int i = 1; i <= n; i++) f[i] = g[i] = 1;
     for (int i = 1; i < n; i++) {
         int a, b;
         cin >> a >> b;
@@ -50,5 +55,5 @@ signed main() {
 
     dfs1(1, 0);
     dfs2(1, 0);
-    for (int i = 1; i <= n; ++i) cout << dp[i] * pd[i] % m << endl;
+    for (int i = 1; i <= n; ++i) cout << f[i] * g[i] % mod << endl;
 }