Submission #1267806

#	Time	Username	Problem	Language	Result	Execution time	Memory
1267806		newbie_t	Torrent (COI16_torrent)	C++20	Compilation error	0 ms	0 KiB

torrent

#include <bits/stdc++.h>
#define vi vector<int>
#define vb vector<bool>
#define vl vector<ll>
#define vii vector<vector<int>>
#define vll vector<vector<ll>>
#define pi pair<int, int>
#define pl pair<ll, ll>
#define vpi vector<pair<int, int>>
#define vpl vector<pair<ll, ll>>
#define a first 
#define b second
#define pb push_back
#define vm vector<mi>
#define vmm vector<vector<mi>>
using namespace std;
const int MOD = 998244353;
using ll = long long;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n,a,b; cin >> n >> a >> b;
    a--,b--;
    vii g(n);
    for(int i = 1; i<n; i++){
        int x,y; cin >> x >> y;
        g[--x].pb(--y);
        g[y].pb(x);
    }
    vi depth(n);
    function<void(int,int)> dfs1;
    dfs1 = [&](int s, int p){
        if(p != -1) depth[s] = depth[p]+1;
        for(int i: g[s]) if(i != p)
            dfs1(i,s);
    };
    dfs1(a,-1);
    vi path{b};
    while(path[path.size()-1] != a)
        for(int i: g[path[path.size()-1]])
            if(depth[i]+1 == depth[path[path.size()-1]]){
                path.pb(i);
                break;
            }
    function<int(int,int,int)> dfs2;
    dfs2 = [&](int s, int p, int stop){
        vi next;
        for(int i: g[s]) if(i != p && i != stop)
            next.pb(dfs2(i,s,stop));
        sort(next.rbegin(),next.rend());
        int ans = 0;
        for(int i = 0; i<next.size(); i++) uMax(ans,next[i]+i);
        return ans+1;
    };
    int lo = 0, hi = path.size()-2;
    while(lo<hi-1){
        int m = (lo+hi)>>1;
        int a1 = dfs2(b,-1,path[m+1]);
        int a2 = dfs2(a,-1,path[m]);
        if(a1<a2) lo = m;
        else hi = m;
    }
    cout << min(max(dfs2(b,-1,path[lo+1]),dfs2(a,-1,path[lo])),max(dfs2(b,-1,path[hi+1]),dfs2(a,-1,path[hi])))-1 << "\n";
}

Compilation message (stderr)

torrent.cpp: In lambda function:
torrent.cpp:52:44: error: 'uMax' was not declared in this scope
   52 |         for(int i = 0; i<next.size(); i++) uMax(ans,next[i]+i);
      |                                            ^~~~