Submission #742049

#	Time	Username	Problem	Language	Result	Execution time	Memory
742049		vjudge1	경주 (Race) (IOI11_race)	C++17	Compilation error	0 ms	0 KiB

race

#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define nmax 200020
#define ii pair<int, int>
#define ll long long
int n, k, ans, cnt[1000100], sz[nmax], r[nmax];
vector<ii> adj[nmax];

inline void minimize(int &a, int b)
{
    if(a == -1 || a > b)
        a = b;
}

int dfs(int u, int p = -1)
{
    sz[u] = 1;
    for(auto x: adj[u]) {
        int v = x.se;
        if(v != p && !r[v]) sz[u] += dfs(v, u);
    }
    return sz[u];
}

int get_centroid(int m, int u, int p = -1)
{
    for(auto x: adj[u]) {
        int v = x.se;
        if(v != p && !r[v] && 2 * sz[v] > m)
            return get_centroid(m, v, u);
    }
    return u;
}

void get_cnt(int sum, bool filling, int u, int p = -1, int depth = 1)
{
    if(sum > k) return;

    if(filling){///neu true thi cap nhat
        minimize(cnt[sum], depth);
        ///cout<<sum<<" "<<cnt[sum]<<endl;
    }
    else {
        if(cnt[k - sum] != -1)
            minimize(ans, depth + cnt[k - sum]);
    }
    for(auto x: adj[u]) {
        int C = x.fi, v = x.se;
        if(v != p && !r[v]) get_cnt(sum + C, filling, v, u, depth + 1);
    }
}

void del(int sum, int u, int p = -1)
{
    if(sum > k) return;
    cnt[sum] = -1;
    for(auto x: adj[u]) {
        int C = x.fi, v = x.se;
        if(v != p && !r[v])
            del(sum + C, v, u);
    }
}

void centroid(int u = 0)
{
    u = get_centroid(dfs(u), u);
    //cout<<u<<" ";
    r[u] = 1;
    cnt[0] = 0;
    for(auto x: adj[u]) {
        int C = x.fi, v = x.se;
        //cout<<v<<" "<<C<<endl;
        if(!r[v]) {
        ///de xu ly tinh huong depth va cnt[k-sum] tren cung mot
        ///nhanh thi khi di vao nhanh do ta
        ///cap nhat ket qua ans truoc roi moi cap nhat tinh
        ///cnt[sum];
            get_cnt(C, false, v);
            get_cnt(C, true, v);
        }
    }
    for(auto x: adj[u]) {
        int C = x.fi, v = x.se;
        if(!r[v]) {
            del(C, v);
        }
    }
    for(auto x: adj[u]) {
        int C = x.fi, v = x.se;
        if(!r[v]) centroid(v);
    }
}

int main()
{

    ios_base::sync_with_stdio(0); cin.tie(0);
	freopen("race.inp", "r", stdin);
	freopen("race.out", "w", stdout);
    cin>>n>>k;
    for(int i = 1; i <= n-1; i++) {
        int u, v, C;
        cin>>u>>v>>C;
        adj[u].push_back(ii(C, v));
        adj[v].push_back(ii(C, u));
    }
    ans = -1;
    memset(cnt, -1, sizeof(cnt));
    centroid();
    cout<<ans<<endl;
    return 0;
}

Compilation message (stderr)

race.cpp: In function 'void centroid(int)':
race.cpp:91:13: warning: unused variable 'C' [-Wunused-variable]
   91 |         int C = x.fi, v = x.se;
      |             ^
race.cpp: In function 'int main()':
race.cpp:100:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  100 |  freopen("race.inp", "r", stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
race.cpp:101:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  101 |  freopen("race.out", "w", stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccywCZgU.o: in function `main':
race.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cceCLvAT.o:grader.cpp:(.text.startup+0x0): first defined here
/usr/bin/ld: /tmp/cceCLvAT.o: in function `main':
grader.cpp:(.text.startup+0x28): undefined reference to `best_path(int, int, int (*) [2], int*)'
collect2: error: ld returned 1 exit status