Submission #956145

#	Time	Username	Problem	Language	Result	Execution time	Memory
956145		caterpillow	Cats or Dogs (JOI18_catdog)	C++17	Compilation error	0 ms	0 KiB

catdog

#include <bits/stdc++.h>
#include "catdog.h"

using namespace std;

using ll = long long;
using pl = pair<ll, ll>;
#define vt vector
#define f first
#define s second
#define all(x) x.begin(), x.end() 
#define pb push_back
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define ROF(i, a, b) for (int i = (b) - 1; i >= (a); i--)
#define F0R(i, b) FOR (i, 0, b)
#define endl '\n'
#define debug(x) do{auto _x = x; cerr << #x << " = " << _x << endl;} while(0)
const ll INF = 1e18;

int n;
vt<vt<int>> adj;
vt<int> state;

pl dfs(int u, int par = -1) {
    ll cat = 0, dog = 0;
    for (int v : adj[u]) {
        if (v == par) continue;
        pl res = dfs(v, u);
        cat += res.f;
        dog += res.s;
    }
    pl res;
    if (state[u] == 1) dog = INF;
    if (state[u] == 2) cat = INF;
    res = {min(cat, dog + 1), min(cat + 1, dog)};
    return res;
}

int solve() {
    pl res = dfs(0);
    return min(res.f, res.s);
}

void initialize(int N, vt<int> A, vt<int> B) {
    n = N;
    adj.resize(n);
    state.resize(n);
    F0R (i, n - 1) {
        adj[A[i] - 1].pb(B[i] - 1);
        adj[B[i] - 1].pb(A[i] - 1);
    }
}

int cat(int v) {
    v--;
    state[v] = 1;
    return solve();
}

int dog(int v) {
    v--;
    state[v] = 2;
    return solve();
}

int neighbor(int v) {
    v--;
    state[v] = 0;
    return solve();
}

main() {
    cin.tie(0)->sync_with_stdio(0);

    int n; cin >> n;
    vt<int> a(n - 1), b(n - 1);
    F0R (i, n - 1) {
        cin >> a[i] >> b[i];
    }
    initialize(n, a, b);
    int q; cin >> q;
    F0R (i, q) {
        int t, u; cin >> t >> u;
        int res;
        if (t == 1) res = cat(u);
        else if (t == 2) res = dog(u);
        else if (t == 3) res = neighbor(u);
        cout << res << endl;
    }
}

Compilation message (stderr)

catdog.cpp:72:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   72 | main() {
      | ^~~~
catdog.cpp: In function 'int main()':
catdog.cpp:16:14: warning: 'res' may be used uninitialized in this function [-Wmaybe-uninitialized]
   16 | #define endl '\n'
      |              ^~~~
catdog.cpp:84:13: note: 'res' was declared here
   84 |         int res;
      |             ^~~
/usr/bin/ld: /tmp/ccgiECbh.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccA0xuXi.o:catdog.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status