func_code_string: #include <bits/stdc++.h>   using namespace std;   int gi() {     int x = 0, w = 1;     char ch = getchar();     while ((ch <  0  || ch >  9 ) && ch !=  - ) ch = getchar();     if (ch ==  - ) w = 0, ch = getchar();     while (ch >=  0  && ch <=  9 )       x = (x << 3) + (x << 1) + ch -  0 , ch = getchar();     return w ? x : -x;   }   const int N = 4e5 + 5;   int n, m, col[N], fa[N];   long long ans[N];   vector<int> E[N];   vector<pair<int, int> > vec[N];   namespace lct {   int fa[N], ch[2][N], sz[N], si[N];   long long sz2[N], si2[N];   bool son(int x) { return x == ch[1][fa[x]]; }   bool isrt(int x) { return x != ch[0][fa[x]] && x != ch[1][fa[x]]; }   void up(int x) {     sz[x] = sz[ch[0][x]] + sz[ch[1][x]] + si[x];     sz2[x] = 1ll * sz[ch[0][x]] * sz[ch[0][x]] +              1ll * sz[ch[1][x]] * sz[ch[1][x]] + si2[x];   }   void rotate(int x) {     int y = fa[x], z = fa[y], c = son(x);     ch[c][y] = ch[c ^ 1][x];     if (ch[c][y]) fa[ch[c][y]] = y;     fa[x] = z;     if (!isrt(y)) ch[son(y)][z] = x;     ch[c ^ 1][x] = y;     fa[y] = x;     up(y);   }   void splay(int x) {     for (int y = fa[x]; !isrt(x); rotate(x), y = fa[x])       if (!isrt(y)) rotate(son(x) ^ son(y) ? x : y);     up(x);   }   void access(int x) {     for (int y = 0; x; y = x, x = fa[x]) {       splay(x);       si[x] += sz[ch[1][x]];       si2[x] += 1ll * sz[ch[1][x]] * sz[ch[1][x]];       ch[1][x] = y;       si[x] -= sz[y];       si2[x] -= 1ll * sz[y] * sz[y];       up(x);     }   }   void link(int x, int y) {     access(y);     splay(y);     splay(x);     fa[x] = y;     si[y] += sz[x];     si2[y] += 1ll * sz[x] * sz[x];     up(y);   }   void cut(int x, int y) {     access(x);     access(y);     splay(y);     splay(x);     fa[x] = 0;     si[y] -= sz[x];     si2[y] -= 1ll * sz[x] * sz[x];     up(y);   }   int findrt(int x) {     access(x);     splay(x);     while (ch[0][x]) x = ch[0][x];     splay(x);     return x;   }   long long query(int x) {     splay(x);     return sz2[x];   }   void init() {     for (int i = 1; i <= n + 1; ++i) sz[i] = si[i] = 1;     for (int i = 1; i <= n; ++i) link(i, ::fa[i]);   }   }  // namespace lct   void dfs(int u) {     for (int v : E[u])       if (v != fa[u]) fa[v] = u, dfs(v);   }   int main() {     n = gi();     m = gi();     for (int i = 1; i <= n; ++i) col[i] = gi();     for (int i = 1; i < n; ++i) {       int x = gi(), y = gi();       E[x].push_back(y);       E[y].push_back(x);     }     fa[1] = n + 1;     dfs(1);     for (int i = 1; i <= n; ++i) vec[col[i]].push_back(make_pair(0, i << 1 | 1));     for (int i = 1; i <= m; ++i) {       int x = gi(), y = gi();       vec[col[x]].push_back(make_pair(i, x << 1));       col[x] = y;       vec[col[x]].push_back(make_pair(i, x << 1 | 1));     }     for (int i = 1; i <= n; ++i) vec[col[i]].push_back(make_pair(m + 1, i << 1));     lct::init();     for (int i = 1; i <= n; ++i)       for (auto x : vec[i]) {         int u = x.second >> 1, f = lct::findrt(fa[u]);         if (x.second & 1) {           ans[x.first] += lct::query(f);           lct::cut(u, fa[u]);           ans[x.first] -= lct::query(u) + lct::query(f);         } else {           ans[x.first] += lct::query(u) + lct::query(f);           lct::link(u, fa[u]);           ans[x.first] -= lct::query(f);         }       }     for (int i = 1; i <= m; ++i) ans[i] += ans[i - 1];     for (int i = 0; i <= m; ++i) printf( %lld n , ans[i]);     return 0;   }   