Language: C++

#include<bits/stdc++.h>
#include<string>
#include<vector>
using namespace std;
typedef pair<int, int>P;
typedef long long ll;
#define rep(i,n)for(ll i=0;i<n;++i)
#define exrep(i, a, b) for(ll i = a; i <= b; i++)
#define out(x) cout << x << endl
#define exout(x) printf("%.10f\n", x)
#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define pb push_back
#define re0 return 0
const ll MOD = 1000000007;
const ll INF = 1e16;
const ll MAX_N = 5000100;
//max=({});
//条件式が真ならwhileの中身を回し続ける
//printf("%d\n", ans);

//pairの入力
//vector<pair<ll, ll>>work(n);
//rep(i, n) {
//	ll a, b;
//	cin >> a >> b;
//	work[i] = make_pair(a, b);
//for(auto p:mp)(mapの探索)
//printf("%.10f\n",なんちゃら)
//最大公約数
ll gcd(ll x, ll y) {
	return y ? gcd(y, x % y) : x;
}

ll lcm(ll x, ll y) {
	if (x == 0 || y == 0)return 0;
	return (x / gcd(x, y) * y);
}

//組み合わせの余りを求める
ll fac[MAX_N], finv[MAX_N], inv[MAX_N];
void COMinit() {
	fac[0] = fac[1] = 1;
	finv[0] = finv[1] = 1;
	inv[1] = 1;
	for (int i = 2; i < MAX_N; i++) {
		fac[i] = fac[i - 1] * i % MOD;
		inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
		finv[i] = finv[i - 1] * inv[i] % MOD;
	}
}

// 二項係数計算
long long COM(ll n, ll k) {
	if (n < k) return 0;
	if (n < 0 || k < 0) return 0;
	return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}

ll dx[4] = { 0,0,-1,1 };
ll dy[4] = { -1,1,0,0 };
ll dp[101010];

//union-find木について
ll par[101010];
ll rank2[101010];

void init(ll n) {
	rep(i, n) {
		par[i] = i;
		rank2[i] = 0;
	}
}

ll find(ll x) {
	if (par[x] == x) {
		return x;
	}
	else {
		return par[x] = find(par[x]);
	}
}

void unite(ll x, ll y) {
	x = find(x);
	y = find(y);
	if (x == y)return;
	if (rank2[x] < rank2[y]) {
		par[x] = y;
	}
	else {
		par[y] = x;
		if (rank2[x] == rank2[y]) {
			rank2[x]++;
		}
	}
}

long long modpow(long long a, long long n, long long mod) {
	long long res = 1;
	while (n > 0) {
		if (n & 1) res = res * a % mod;
		a = a * a % mod;
		n >>= 1;
	}
	return res;
}

vector < vector<pair<ll, ll>>to;
vector<ll>ans;

void dfs(ll x,ll c=-1,ll p=-1) {
	ll k = 1;
	for (auto v : to[x]) {
		ll ve = v.second;
		ll ed = v.first;
		if (ve == p)continue;
		if (k == col)k++;
		ans[ed] = k;
		k++;
		dfs(ve, cl[ed], x);
	}
}

//long longしか使わない
//素数は1より大きい
int main() {
	ll n;
	cin >> n;
	to.resize(n);
	ans.resize(n - 1);
	rep(i, n - 1) {
		ll a, b;
		cin >> a >> b;
		a--;
		b--;
		to[a].push_back(i, b);
		to[b].push_back(i, a);
	}
	dfs(0);
	ll res = 0;
	rep(i, n) {
		res = max(res, to[i].size());
	}
	cout << res << endl;
	rep(i, n - 1) {
		cout << ans[i] << endl;
	}
	return 0;
}


Compiler output:
a.cc:111:30: error: template argument 1 is invalid
  111 | vector < vector<pair<ll, ll>>to;
      |                              ^~
a.cc:111:30: error: template argument 2 is invalid
a.cc: In function 'void dfs(ll, ll, ll)':
a.cc:116:23: error: 'to' was not declared in this scope; did you mean 'tm'?
  116 |         for (auto v : to[x]) {
      |                       ^~
      |                       tm
a.cc:120:26: error: 'col' was not declared in this scope; did you mean 'cosl'?
  120 |                 if (k == col)k++;
      |                          ^~~
      |                          cosl
a.cc:123:25: error: 'cl' was not declared in this scope; did you mean 'c'?
  123 |                 dfs(ve, cl[ed], x);
      |                         ^~
      |                         c
a.cc: In function 'int main()':
a.cc:132:9: error: 'to' was not declared in this scope; did you mean 'tm'?
  132 |         to.resize(n);
      |         ^~
      |         tm