func_code_string: #include <bits/stdc++.h>   void dfs(int x);   struct node {     int n, h;   } h[100001];   bool operator<(const node &A, const node &B) { return A.h < B.h; }   std::vector<int> map[100001];   int range[100001][2];   void init(int n);   int getmax(int f, int r);   void set(int x, int v);   int imax[100001][3];   int dmax[100001][3];   int main() {     int n;     int i, j;     int t, a, b;     scanf( %d , &n);     for (i = 1; i <= n; i++) {       scanf( %d , &h[i].h);       h[i].n = i;     }     std::sort(h + 1, h + n + 1);     for (i = 1; i < n; i++) {       scanf( %d%d , &a, &b);       map[a].push_back(b);       map[b].push_back(a);     }     dfs(1);     init(n);     for (i = 1; i <= n; i = j) {       for (j = i; j <= n && h[j].h == h[i].h; j++) {         int x = h[j].n;         for (int k = 0; k < map[x].size(); k++) {           int xx = map[x][k];           if (range[xx][0] < range[x][0]) continue;           int t = getmax(range[xx][0], range[xx][1]);           if (t > imax[x][0]) {             imax[x][2] = imax[x][0];             imax[x][1] = xx;             imax[x][0] = t;           } else if (t > imax[x][2]) {             imax[x][2] = t;           }         }       }       for (j = i; j <= n && h[j].h == h[i].h; j++) {         int x = h[j].n;         set(range[x][0], imax[x][0] + 1);       }     }     init(n);     for (i = n; i >= 1; i = j) {       for (j = i; j >= 1 && h[j].h == h[i].h; j--) {         int x = h[j].n;         for (int k = 0; k < map[x].size(); k++) {           int xx = map[x][k];           if (range[xx][0] < range[x][0]) continue;           int t = getmax(range[xx][0], range[xx][1]);           if (t > dmax[x][0]) {             dmax[x][2] = dmax[x][0];             dmax[x][1] = xx;             dmax[x][0] = t;           } else if (t > dmax[x][2]) {             dmax[x][2] = t;           }         }       }       for (j = i; j >= 1 && h[j].h == h[i].h; j--) {         int x = h[j].n;         set(range[x][0], dmax[x][0] + 1);       }     }     int ans = 0;     for (i = 1; i <= n; i++) {       if (imax[i][1] == dmax[i][1]) {         if (ans < imax[i][0] + dmax[i][2] + 1) ans = imax[i][0] + dmax[i][2] + 1;         if (ans < imax[i][2] + dmax[i][0] + 1) ans = imax[i][2] + dmax[i][0] + 1;       } else {         if (ans < imax[i][0] + dmax[i][0] + 1) ans = imax[i][0] + dmax[i][0] + 1;       }     }     init(n);     for (i = 1; i <= n; i = j) {       for (j = i; j <= n && h[j].h == h[i].h; j++) {         int x = h[j].n;         int t = getmax(range[x][1] + 1, n);         if (ans < t + dmax[x][0] + 1) ans = t + dmax[x][0] + 1;       }       for (j = i; j <= n && h[j].h == h[i].h; j++) {         int x = h[j].n;         set(range[x][0], imax[x][0] + 1);       }     }     init(n);     for (i = n; i >= 1; i = j) {       for (j = i; j >= 1 && h[j].h == h[i].h; j--) {         int x = h[j].n;         int t = getmax(range[x][1] + 1, n);         if (ans < t + imax[x][0] + 1) ans = t + imax[x][0] + 1;       }       for (j = i; j >= 1 && h[j].h == h[i].h; j--) {         int x = h[j].n;         set(range[x][0], dmax[x][0] + 1);       }     }     printf( %d , ans);     return 0;   }   int dT = 0;   void dfs(int x) {     range[x][0] = ++dT;     for (int i = 0; i < map[x].size(); i++) {       int xx = map[x][i];       if (range[xx][0] != 0) continue;       dfs(xx);     }     range[x][1] = dT;   }   int IT[400001];   int b;   void init(int n) {     for (b = 1; b <= n; b *= 2)       ;     for (int i = b * 2; i >= 1; i--) IT[i] = 0;   }   int max(int a, int b) { return a > b ? a : b; }   int getmax(int f, int r) {     f += b;     r += b;     int m = 0;     while (f < r) {       if (f % 2 == 1) m = max(m, IT[f++]);       if (r % 2 == 0) m = max(m, IT[r--]);       f /= 2;       r /= 2;     }     if (f == r) m = max(m, IT[f]);     return m;   }   void set(int x, int v) {     IT[x += b] = v;     while (x /= 2) IT[x] = max(IT[x * 2], IT[x * 2 + 1]);   }   