Merge pull request rachitiitr#7 from rachitkewl/master

Added Small To Large in Tree

Author: rachitiitr

Tree/SmallToLarge.cpp

@@ -0,0 +1,75 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define gc getchar_unlocked
+#define fo(i,n) for(i=0;i<n;i++)
+#define Fo(i,k,n) for(i=k;i<n;i++)
+#define ll long long
+#define si(x)	scanf("%d",&x)
+#define sl(x)	scanf("%I64d",&x)
+#define ss(s)	scanf("%s",s)
+#define pb push_back
+#define mp make_pair
+#define F first
+#define S second
+#define all(x) x.begin(), x.end()
+#define clr(x) memset(x, 0, sizeof(x))
+#define sortall(x) sort(all(x))
+#define tr(it, a) for(auto it = a.begin(); it != a.end(); it++)
+#define PI 3.1415926535897932384626
+typedef pair<int, int>	pii;
+typedef pair<ll, ll>	pll;
+typedef vector<int>		vi;
+typedef vector<ll>		vl;
+typedef vector<pii>		vpii;
+typedef vector<pll>		vpll;
+typedef vector<vi>		vvi;
+typedef vector<vl>		vvl;
+const int mod = 1000000007;
+const int N = 3e5;
+vi g[N];
+int a[N];
+
+//BEGIN
+map<int, ll> cnt[N], val[N];
+int id[N], col[N];
+ll ans[N];
+//http://codeforces.com/contest/600/problem/E
+//Notice how ids of u and v swap due to &
+void merge(int &u, int &v){
+	if ((int)cnt[u].size() > (int)cnt[v].size()) swap(u, v);
+	for (auto it: cnt[u]){
+		int c = it.F; int occ = it.S;
+		val[v][cnt[v][c]] -= c;
+		cnt[v][c] += occ;
+		val[v][cnt[v][c]] += c;
+	}
+}
+void dfs(int u, int par){
+	id[u] = u;
+	cnt[u][col[u]] = 1;
+	val[u][1] = col[u];
+	for(int v: g[u]){
+		if (v == par) continue;
+		dfs(v, u);
+		merge(id[v], id[u]);
+	}
+	ans[u] = val[id[u]].rbegin()->S;
+}
+//END
+int main()
+{
+	ios_base::sync_with_stdio(false);
+	cin.tie(NULL);
+	int i,n,k,j, u, v;
+	cin>>n;
+	fo(i, n) cin>>col[i+1];
+	fo(i, n-1){
+		cin>>u>>v;
+		g[u].pb(v);
+		g[v].pb(u);
+	}
+	dfs(1, 0);
+    Fo(i, 1, n+1) cout<<ans[i]<<" ";
+	return 0;
+}
+