Submission #1119095

#	Time	Username	Problem	Language	Result	Execution time	Memory
1119095		kiethm07	Synchronization (JOI13_synchronization)	C++11	0 / 100	8053 ms	13384 KiB

synchronization

#include <bits/stdc++.h>

#define pii pair<int,int>
#define pli pair<long long,int>
#define plii pair<long long,pii>
#define fi first
#define se second

#define vi vector<int>
#define vii vector<pii>
#define all(x) x.begin(),x.end()
#define compact(x) x.erase(unique(all(x)),x.end())
#define pb(x) push_back(x)

using namespace std;

typedef long long ll;
typedef long double ld;

const int inf = 1e9;
const ll linf = 1e16;
const double PI = acos(-1);
const int N = 1e5 + 5;

struct edge{
    int u,v,w;
    edge(){}
    edge(int a,int b,int c){
        u = a,v = b,w = c;
    }
};

edge e[N];
vector<int> a[N];
int n,m,q;
int pa[N];
bool active[N];
int val[N];

void dfs(int u,int p){
    for (int v : a[u]){
        if (v == p) continue;
        pa[v] = u;
        dfs(v,u);
    }
}

int getNode(int u){
    while(active[pa[u]]) u = pa[u];
    return u;
}

void query(int id){
    if (e[id].v == pa[e[id].u]) swap(e[id].u, e[id].v);
    int u = e[id].u;
    int v = e[id].v;
    int f = getNode(u);
    int tmp = val[f] + val[v] - e[id].w;
    val[f] = val[v] = e[id].w = tmp;
    active[v] ^= 1;
}

int main(){
    #define TEXT "synchronization"
    cin.tie(0) -> sync_with_stdio(0);
    if (fopen(TEXT".inp","r")){
        freopen(TEXT".inp","r",stdin);
        freopen(TEXT".ans","w",stdout);
    }
    cin >> n >> m >> q;
    for (int i = 1; i < n; i++){
        int u,v;
        cin >> u >> v;
        a[u].push_back(v);
        a[v].push_back(u);
        e[i] = edge(u,v,0);
    }
    dfs(1,-1);
    while(m--){
        int id;
        cin >> id;
        query(id);
    }
    while(q--){
        int x;
        cin >> x;
        int f = getNode(x);
        cout << val[f] << "\n";
    }
    return 0;
}

Compilation message (stderr)

synchronization.cpp: In function 'int main()':
synchronization.cpp:67:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |         freopen(TEXT".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
synchronization.cpp:68:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |         freopen(TEXT".ans","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 10
• Subtask 4: 0 / 20
• Subtask 5: 0 / 40