Shared code

/*
*    Author:Jx07
*    Created:Friday, 23.01.2026 04:57 PM (GMT+5:30)
*/
#include<bits/stdc++.h>

#ifdef JAI
#include "algo/debug.cpp"
#else
#define debug(...)
#endif
 
using namespace std;
mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());
#define int long long 
#define all(v) v.begin(), v.end()

#define peace
const int tt=0;
int MOD=1e9+7;//998244353;
int LOG,n;
vector<vector<int>> graph(n);
vector<int> depth(n, 0);
vector<vector<int>> binl(n, vector<int>(LOG));

void dfs(int node, int par) {
    for(auto child : graph[node]) {
        if(child == par) {
            continue;
        }
        depth[child] = depth[node] + 1;
        binl[child][0] = node;
        for(int i = 1; i < LOG; i++) {
            binl[child][i] = binl[binl[child][i - 1]][i - 1];
        }
        dfs(child, node);
    }
}
 
int get_lca(int u, int v) {
    if(depth[u] < depth[v]) {
        swap(u, v);
    }
    int k = depth[u] - depth[v];
    for(int j = LOG - 1; j >= 0; j--) {
        if(k & (1LL << j)) {
            u = binl[u][j];
            k^=(1LL<<j);
        }
        if(k==0)break;
    }
    if(u == v) {
        return u;
    }
    for(int j = LOG - 1; j >= 0; j--) {
        if(binl[u][j] != binl[v][j]) {
            u = binl[u][j];
            v = binl[v][j];
            if(u==v)break;
        }
    }
    return binl[u][0];
}
 
void solve(int tc){
    int q;
    cin >> n >> q;
    LOG = log2(n) + 1;
    graph.resize(n,vector<int>());
    depth.resize(n,0);
    binl.resize(n,vector<int>(LOG));
    for(int i = 0; i < n - 1; i++) {
        int u, v;
        cin >> u >> v;
        u--; v--;
        graph[u].push_back(v);
        graph[v].push_back(u);
    }
    // debug(n);
    dfs(0, -1);
    while(q--) {
        int u, v;
        cin >> u >> v;
        u--; v--;
        int x = get_lca(u, v);
        int dist = depth[u] + depth[v] - (2 * depth[x]);
        cout << dist << endl;
    }







}


signed main() {
    #if defined(JAI) && defined(peace)
        freopen("input.txt", "r", stdin);  
        freopen("output.txt", "w", stdout); 
        clock_t T = clock();
    #endif

    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    
    int t=1;
    if(tt)cin>>t;
    
    for(int i=1;i<=t;i++){
        solve(i);
    }

    #if defined(JAI) && defined(peace)
        cout << "\nTime : " << ((float)(clock() - T)*1000) / CLOCKS_PER_SEC << " ms";
    #endif

    return 0;
}