Submission #852915

#	Time	Username	Problem	Language	Result	Execution time	Memory
852915		Trisanu_Das	The Xana coup (BOI21_xanadu)	C++17	Compilation error	0 ms	0 KiB

xanadu

#include <bits/stdc++.h>
using namespace std;

int n,f[1000005][2][2],C[1000005];
vector <int> G[1000005];
void dfs(int u, int p){
    for(int i = 0; i <= 1; i++){
        f[u][i][C[u]^i] = i;
        f[u][i][C[u]^i^1] = n + 1;
    }
    for(int v : G[u])if(v!=fa){
        dfs(v,u);
        for(int i = 0; i <= 1; i++){
            int f0=f[u][i][0],f1=f[u][i][1];
            f[u][i][0]=min(n+1,min(f0+f[v][0][i],f1+f[v][1][i]));
            f[u][i][1]=min(n+1,min(f0+f[v][1][i],f1+f[v][0][i]));
        }
    }
}
int main(){
    cin >> n;
    for(int i = 2; i <= n; i++){
        int u,v;
        cin >> u >> v;
        G[u].push_back(v),G[v].push_back(u);
    }
    rep(i,1,n)cin >> C[i];
    dfs(1,0);
    int ans=min(f[1][0][0],f[1][1][0]);
    if(ans>n) cout << "impossible\n";
    else cout << ans << '\n';
} 

Compilation message (stderr)

xanadu.cpp: In function 'void dfs(int, int)':
xanadu.cpp:11:28: error: 'fa' was not declared in this scope; did you mean 'f'?
   11 |     for(int v : G[u])if(v!=fa){
      |                            ^~
      |                            f
xanadu.cpp: In function 'int main()':
xanadu.cpp:27:9: error: 'i' was not declared in this scope
   27 |     rep(i,1,n)cin >> C[i];
      |         ^
xanadu.cpp:27:5: error: 'rep' was not declared in this scope
   27 |     rep(i,1,n)cin >> C[i];
      |     ^~~