Shared code

#include<bits/stdc++.h>
#define ll long long int
using namespace std;
ll M = 1e9 + 7;

// author: Krishna Sharma

bool is_ancestor(int a, int b, vector<pair<int, int>>&inout) {
    if (a == -1) return true;
    return (inout[a].first <= inout[b].first && inout[a].second >= inout[b].second);
}
int lca(int a, int b, vector<pair<int, int>>&inout, vector<vector<int>> &par) {
    if (is_ancestor(a, b, inout)) return a;
    if (is_ancestor(b, a, inout)) return b;
    for (int k = 32; k >= 0; k--) {
        int parx = par[a][k];
        if (!is_ancestor(parx, b, inout)) {
            a = parx;
        }
    }
    return par[a][0];
}
int fn(int n, vector<vector<int>> &v, vector<pair<int, int>>&inout, int c, int par) {
    inout[n].first = c;
    for (auto i : v[n]) {
        if (i == par) continue;
        c = fn(i, v, inout, c + 1, n);
    }
    inout[n].second = c + 1;
    return c + 1;
}
void dfs(int n, vector<vector<int>> &v, vector<int>&level, int par, vector<vector<int>> &p) {
    p[n][0] = par;
    for (auto i : v[n]) {
        if (i == par) continue;
        level[i] = level[n] + 1;
        dfs(i, v, level, n, p);
    }
}
void fns(int n, vector<vector<int>> &v, vector<long long> &values, int par) {
    for (auto i : v[n]) {
        if (i == par) continue;
        fns(i, v, values, n);
        values[n] = values[n] + values[i];
    }
}
int main() {
    int n, m;
    cin >> n >> m;
    vector<vector<int>> v(n + 1);
    for (int i = 0; i < n - 1; i++) {
        int x, y;
        cin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    vector<pair<int, int>> paths;
    for (int i = 0; i < m; i++) {
        int x, y;
        cin >> x >> y;
        paths.push_back({x, y});
    }
    vector<int> level(n + 1, 0);
    vector<pair<int, int>>inout(n + 1, {0, 0});
    fn(1, v, inout, 0, -1);
    vector<vector<int>> par(n + 1, vector<int>(64, -1));
    dfs(1, v, level, -1, par);
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j < 63; j++) {
            int take = par[i][j - 1];
            int parent = -1;
            if (take != -1)  parent = par[take][j - 1];
            par[i][j] = parent;
        }
    }
    vector<long long> values(n + 1, 0);
    for (auto i : paths) {
        int a = i.first;
        int b = i.second;
        if (level[a] > level[b]) swap(a, b);
        if (is_ancestor(a, b, inout)) {
            int take = par[a][0];
            if (take == -1);
            else values[take]--;
            values[b]++;
        }
        else {
            int ans = lca(a, b, inout, par);
            int take = par[ans][0];
            if (take == -1);
            else values[take]--;
            values[ans]--;
            values[a]++;
            values[b]++;
        }
    }
    fns(1, v, values, -1);
    for (int i = 1; i <= n; i++) cout << values[i] << " ";
}