제출 #679667

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
679667		keta_tsimakuridze	Mergers (JOI19_mergers)	C++14	0 / 100	159 ms	34752 KiB

mergers

#include<bits/stdc++.h>
#define f first
#define s second
#define int long long
#define pii pair<int,int>
using namespace std;
const int N = 2e5 + 5, mod = 1e9 + 7; // !
int t, p[N], P[N][20], X[N], in[N], out[N];
int ans = 0, timer = 0;
vector<int> V[N], x[N];
bool cmp(int u, int v) {
    return (in[u] < in[v]);
}
int find(int x) {
    return (p[x] == x ? x : p[x] = find(p[x]));
}

void dfs0(int u) {
    in[u] = ++timer;
    for(int i = 1; i <= 18; i++) P[u][i] = P[P[u][i - 1]][i - 1];
    for(int i = 0; i < V[u].size(); i++) {
        if(V[u][i] == P[u][0]) continue;
        P[V[u][i]][0] = u;
        dfs0(V[u][i]);
    }
    out[u] = timer;
}
bool check(int u, int v) {
    return (in[u] <= in[v] && out[v] <= out[u]);
}
int lca(int u, int v) {
    if(check(u, v)) return u;
    if(check(v, u)) return v;

    for(int i = 18; i >= 0; i--) {
        if(P[u][i] && !check(P[u][i], v)) u = P[u][i];
    }
    return P[u][0];
}
void up(int u, int v, int lca) {
    int cur = u;
    while(true) {
        cur = find(cur);
        if(cur == 1 || find(cur) == find(lca)) break;
        p[cur] = find(P[cur][0]);
        cur = p[cur];
    }
}
void dfs(int u) {

    for(int i = 0; i < V[u].size(); i++) {
        dfs(V[u][i]);
        X[u] += X[V[u][i]];
    }
    ans += ((int)V[u].size() == 1);
}
main(){
    int n, m;
    cin >> n >> m;
    for(int i =1; i <= n; i++) p[i] = i;
    for(int i = 2; i <= n; i++) {
        int u, v;
        cin >> u >> v;
        V[u].push_back(v);
        V[v].push_back(u);
    }
    dfs0(1);
    for(int i = 1; i <= n; i++) {
        int a; cin >> a;
        x[a].push_back(i);
    }
    for(int i = 1; i <= m; i++) {

        sort(x[i].begin(), x[i].end(), cmp);

        for(int j = 1; j < x[i].size(); j++) {

            int u = x[i][j - 1], v = x[i][j];
            int l = lca(u, v);
            up(u, v, l);
            up(v, u, l);
        }
    }
    for(int i = 1; i <= n; i++) V[i].clear();
    for(int i = 2; i <= n; i++) if(find(i) != find(P[i][0])) V[find(P[i][0])].push_back(find(i));
    dfs(1);
    cout << (ans + 1) /2;

 }

컴파일 시 표준 에러 (stderr) 메시지

mergers.cpp: In function 'void dfs0(long long int)':
mergers.cpp:21:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |     for(int i = 0; i < V[u].size(); i++) {
      |                    ~~^~~~~~~~~~~~~
mergers.cpp: In function 'void dfs(long long int)':
mergers.cpp:51:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |     for(int i = 0; i < V[u].size(); i++) {
      |                    ~~^~~~~~~~~~~~~
mergers.cpp: At global scope:
mergers.cpp:57:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   57 | main(){
      | ^~~~
mergers.cpp: In function 'int main()':
mergers.cpp:76:26: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   76 |         for(int j = 1; j < x[i].size(); j++) {
      |                        ~~^~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 24
• Subtask 3: 0 / 14
• Subtask 4: 0 / 22
• Subtask 5: 0 / 30