fork download
copy 
  1. #include<bits/stdc++.h>
  2. using namespace std;
  3. #define endl '\n'
  4. #define int long long int
  5. const int MOD = 1000000007;
  6. const int MOD2 = 998244353;
  7. const int INF = LLONG_MAX / 2;
  8. const int MAXN = 100000;
  9. int primes[1000000];
  10.  
  11. /*void seive() {
  12.     fill(primes, primes + 1000000, 1);
  13.     primes[0] = primes[1] = 0;
  14.     for (int i = 2; i * i < 1000000; i++) {
  15.         if (primes[i]) {
  16.             for (int j = i * i; j < 1000000; j += i) {
  17.                 primes[j] = 0;
  18.             }
  19.         }
  20.     }
  21. }
  22.  
  23. bool isPrime(int n) {
  24.     if (n <= 1) return false;
  25.     for (int i = 2; i * i <= n; i++) {
  26.         if (n % i == 0) return false;
  27.     }
  28.     return true;
  29. }
  30.  
  31. int gcd(int a, int b) {
  32.     if (a == 0) return b;
  33.     return gcd(b % a, a);
  34. }*/
  35.  
  36. int power(int a, int b, int mod) {
  37.     int res = 1;
  38.     a %= mod;
  39.     while (b > 0) {
  40.         if (b & 1) res = res * a % mod;
  41.         a = a * a % mod;
  42.         b >>= 1;
  43.     }
  44.     return res;
  45. }
  46.  
  47. // nCr % MOD for n < MOD
  48. int nCrModP(int n, int r) {
  49.     if (r > n) return 0;
  50.     if (r == 0 || r == n) return 1;
  51.  
  52.     int numerator = 1, denominator = 1;
  53.     for (int i = 0; i < r; i++) {
  54.         numerator = (numerator * (n - i)) % MOD;
  55.         denominator = (denominator * (i + 1)) % MOD;
  56.     }
  57.     return (numerator * power(denominator, MOD - 2, MOD)) % MOD;
  58. }
  59.  
  60. // Lucas's Theorem
  61. int lucas(int n, int r) {
  62.     if (r == 0) return 1;
  63.     return (lucas(n / MOD, r / MOD) * nCrModP(n % MOD, r % MOD)) % MOD;
  64. }
  65. void primefactorisation(int n , unordered_map<int,int>&m){
  66.     for(int i = 2 ; i<=sqrt(n) ; i++){
  67.         if(n%i==0){
  68.             int cnt = 0;
  69.             while(n%i==0){
  70.                cnt++;
  71.                n /= i;
  72.             }
  73.             if(cnt%2!=0){
  74.                 m[i]++;
  75.             }
  76.         }
  77.     }
  78.     if(n>1){
  79.         m[n]++;
  80.     }
  81. }
  82. void dfs(int node , bool visited[] , vector<int>A[] , int values[] , int &c , unordered_map<int,int>&m1){
  83.     visited[node] = true;
  84.     c = c+m1[values[node]];
  85.     m1[values[node]]++;
  86.     for(auto node1 : A[node]){
  87.         if(!visited[node1]){
  88.             visited[node1] = true;
  89.             dfs(node1,visited,A,values,c,m1);
  90.         }
  91.     }
  92.     m1[values[node]]--;
  93. }
  94. void solve() {
  95.     int n;
  96.     cin>>n;
  97.     int values[n];
  98.     for(int i = 0 ; i<n ; i++){
  99.         cin>>values[i];
  100.         unordered_map<int,int>m;
  101.         primefactorisation(values[i],m);
  102.         int ans = 1;
  103.         for(auto i:m){
  104.            if(i.second%2!=0){
  105.               ans *= i.first;
  106.            }
  107.         }
  108.         values[i] = ans;
  109.         m.clear();
  110.     }
  111.     vector<int>A[n];
  112.     bool visited[n+1];
  113.     fill(visited,visited+n,false);
  114.     unordered_map<int,int>m1;
  115.     int c = 0;
  116.     for(int i = 0 ; i<n-1 ; i++){
  117.        int a,b;
  118.        cin>>a>>b;
  119.        A[a].push_back(b);
  120.        A[b].push_back(a);
  121.     }
  122.     dfs(0,visited,A,values,c,m1);
  123.     cout<<c<<endl;
  124. }
  125.  
  126. signed main() {
  127.     ios::sync_with_stdio(false); cin.tie(NULL);
  128.     //int t;
  129.     //cin >> t;
  130.     //while (t--) {
  131.         solve();
  132.     //}
  133.     return 0;
  134. }
  135.  
Success #stdin #stdout 0.01s 5316KB
comments (?)
stdin
copy 
5 
4 2 4 4 4 
0 1
1 2
0 3 
3 4
stdout
copy 
4
https://ideone.com/OXe3OP
language:
C++14 (gcc 8.3)
created:
3 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!