func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 200005;   struct Edge {     int to;     int nxt;   } edge[MAXN << 1];   int n, k, id;   int first[MAXN];   int a[MAXN];   int fa[MAXN];   int f[MAXN];   int g[MAXN];   int sz[MAXN];   void addE(int u, int v) {     edge[++id] = (Edge){v, first[u]};     first[u] = id;   }   void dfsinfo(int u) {     sz[u] = 1;     for (int i = first[u]; i; i = edge[i].nxt)       if (edge[i].to != fa[u]) {         fa[edge[i].to] = u;         dfsinfo(edge[i].to);         sz[u] += sz[edge[i].to];       }   }   void dfsf(int u, int lim) {     int MX = 0, sum = 1;     for (int i = first[u]; i; i = edge[i].nxt)       if (edge[i].to != fa[u] && a[edge[i].to] >= lim) {         dfsf(edge[i].to, lim);         if (sz[edge[i].to] == f[edge[i].to])           sum += f[edge[i].to];         else           MX = max(MX, f[edge[i].to]);       }     f[u] = MX + sum;   }   void dfsg(int u, int lim) {     int MX1 = 0, MX2 = 0, sum = 1;     for (int i = first[u]; i; i = edge[i].nxt)       if (edge[i].to != fa[u] && a[edge[i].to] >= lim) {         if (sz[edge[i].to] == f[edge[i].to])           sum += f[edge[i].to];         else if (f[edge[i].to] >= MX1) {           MX2 = MX1;           MX1 = f[edge[i].to];         } else if (f[edge[i].to] > MX2)           MX2 = f[edge[i].to];       }     if (n - sz[u] == g[u])       sum += g[u];     else if (g[u] >= MX1) {       MX2 = MX1;       MX1 = g[u];     } else if (g[u] > MX2)       MX2 = g[u];     for (int i = first[u]; i; i = edge[i].nxt)       if (edge[i].to != fa[u] && a[edge[i].to] >= lim) {         if (sz[edge[i].to] == f[edge[i].to])           g[edge[i].to] = sum - f[edge[i].to] + MX1;         else if (f[edge[i].to] == MX1)           g[edge[i].to] = sum + MX2;         else           g[edge[i].to] = sum + MX1;         dfsg(edge[i].to, lim);       }   }   int getans(int lim) {     memset(f, 0, sizeof(f));     memset(g, 0, sizeof(g));     if (a[1] >= lim) {       dfsf(1, lim);       dfsg(1, lim);     }     for (int i = 1; i <= n; i++)       if (a[i] < lim)         for (int j = first[i]; j; j = edge[j].nxt)           if (edge[j].to != fa[i] && a[edge[j].to] >= lim) {             dfsf(edge[j].to, lim);             dfsg(edge[j].to, lim);           }     int res = 0;     for (int i = 1; i <= n; i++) {       if (a[i] < lim) continue;       int MX = 0, sum = 1;       for (int j = first[i]; j; j = edge[j].nxt)         if (a[edge[j].to] >= lim) {           int SZ = 0, FG = 0;           if (edge[j].to == fa[i]) {             SZ = n - sz[i];             FG = g[i];           } else {             SZ = sz[edge[j].to];             FG = f[edge[j].to];           }           if (FG == SZ)             sum += FG;           else             MX = max(MX, FG);         }       res = max(res, MX + sum);     }     return res;   }   int main() {     scanf( %d%d , &n, &k);     for (int i = 1; i <= n; i++) scanf( %d , &a[i]);     for (int u, v, i = 1; i < n; i++) {       scanf( %d%d , &u, &v);       addE(u, v);       addE(v, u);     }     dfsinfo(1);     int low = 1, high = 1000000;     while (low < high) {       int mid = low + high + 1 >> 1;       if (getans(mid) >= k)         low = mid;       else         high = mid - 1;     }     printf( %d n , low);     return 0;   }   