func_code_string: #include <bits/stdc++.h>   using namespace std;   char s[300005];   int n, cnt, p[300005], to[600005], nexti[600005];   int fa[300005], son[300005], dep[300005], len[300005], top[300005],       dfsx[300005], st[300005];   void dfs(int x, int lasti) {     son[x] = 0;     len[x] = 1;     for (int i = p[x]; i != -1; i = nexti[i])       if (to[i] != lasti) {         fa[to[i]] = x;         dep[to[i]] = dep[x] + 1;         dfs(to[i], x);         len[x] += len[to[i]];         if (!son[x] || len[to[i]] > len[son[x]]) son[x] = to[i];       }   }   void DFS(int x, int lasti) {     st[x] = ++cnt;     dfsx[cnt] = x;     if (son[x]) top[son[x]] = top[x], DFS(son[x], x);     for (int i = p[x]; ~i; i = nexti[i])       if (to[i] != lasti && to[i] != son[x]) top[to[i]] = to[i], DFS(to[i], x);   }   int pw[300005], pre[300005], suf[300005];   inline int gethash(int l, int r) {     if (l < r)       return (pre[r] - 1LL * pre[l - 1] * pw[r - l + 1] % 998244353 + 998244353) %              998244353;     else       return (suf[r] - 1LL * suf[l + 1] * pw[l - r + 1] % 998244353 + 998244353) %              998244353;   }   struct Path {     int l, r;     int len() { return abs(r - l) + 1; }     Path(int l = 0, int r = 0) : l(l), r(r) {}   } x[305], y[305];   int getpath(int u, int v, Path *path) {     static Path l[305], r[305];     int totl = 0, totr = 0;     while (top[u] != top[v]) {       if (dep[top[u]] > dep[top[v]]) {         l[++totl] = Path(st[u], st[top[u]]);         u = fa[top[u]];       } else {         r[++totr] = Path(st[top[v]], st[v]);         v = fa[top[v]];       }     }     if (dep[u] > dep[v])       l[++totl] = Path(st[u], st[v]);     else       r[++totr] = Path(st[u], st[v]);     int tot = 0;     for (int i = 1; i <= totl; i++) path[++tot] = l[i];     for (int i = totr; i >= 1; i--) path[++tot] = r[i];     return tot;   }   inline void getlr(Path pa, int len, int &l, int &r) {     if (pa.l < pa.r)       l = pa.l, r = l + len - 1;     else       l = pa.l, r = l - len + 1;   }   inline void update(Path *pa, int &x, int len) {     if (pa[x].len() == len)       pa[x++] = Path();     else if (pa[x].l < pa[x].r)       pa[x].l += len;     else       pa[x].l -= len;   }   bool ck(int cntx, int cnty, int len) {     if (len == 0) return true;     int l, r;     getlr(x[cntx], len, l, r);     int hx = gethash(l, r);     getlr(y[cnty], len, l, r);     int hy = gethash(l, r);     if (hx == hy)       return true;     else       return false;   }   int query(int a, int b, int c, int d) {     int xn = getpath(a, b, x), yn = getpath(c, d, y);     int cntx = 1, cnty = 1, ret = 0;     while (cntx <= xn && cnty <= yn) {       int len = min(x[cntx].len(), y[cnty].len());       if (ck(cntx, cnty, len)) {         update(x, cntx, len);         update(y, cnty, len);         ret += len;       } else {         int ans = 0, L = 0, R = len - 1;         while (L < R) {           len = (L + R + 1) >> 1;           if (ck(cntx, cnty, len))             L = len;           else             R = len - 1;         }         return ret + L;       }     }     return ret;   }   int main() {     scanf( %d%s , &n, s + 1);     memset(p, -1, sizeof p);     for (int i = 1; i < n; i++) {       int u, v;       scanf( %d%d , &u, &v);       cnt++, to[cnt] = v, nexti[cnt] = p[u], p[u] = cnt;       cnt++, to[cnt] = u, nexti[cnt] = p[v], p[v] = cnt;     }     dep[1] = 1;     dfs(1, -1);     cnt = 0;     DFS(1, 1);     pw[0] = 1;     for (int i = 1; i <= n; i++) pw[i] = 1LL * pw[i - 1] * 29 % 998244353;     for (int i = 1; i <= n; i++)       pre[i] = (1LL * pre[i - 1] * 29 + s[dfsx[i]] -  a  + 1) % 998244353;     for (int i = n; i >= 1; i--)       suf[i] = (1LL * suf[i + 1] * 29 + s[dfsx[i]] -  a  + 1) % 998244353;     int q;     scanf( %d , &q);     while (q--) {       int a, b, c, d;       scanf( %d%d%d%d , &a, &b, &c, &d);       printf( %d n , query(a, b, c, d));     }     return 0;   }   