Submission #635930

#	Time	Username	Problem	Language	Result	Execution time	Memory
635930		Cross_Ratio	Toll (APIO13_toll)	C++14	0 / 100	1 ms	340 KiB

toll

#include <bits/stdc++.h>
using namespace std;
struct UnionFind {
    vector<int> root;
    UnionFind(int N) {
        root.resize(N);
        fill(root.begin(),root.end(),-1);
    }
    int Find(int n) {
        if(root[n]<0) return n;
        int r = Find(root[n]);
        root[n] = r;
        return r;
    }
    void Merge(int x, int y) {
        x = Find(x), y = Find(y);
        if(x==y) return;
        root[x] = y;
    }
};
typedef pair<long long int, long long int> P;
long long int dis[20];
long long int D[15];
long long int dfs(int c, int p, vector<vector<P>> adj) {
    dis[c] = D[c];
    for(P k : adj[c]) {
        if(k.first==p) continue;
        dis[c] += dfs(k.first, c, adj);
    }
    return dis[c];
}
int A[15];
int B[15];
long long int C[15];
int S, E;
int N, M;
long long int get_ans(int c, int p) {
    vector<array<long long int, 3>> V;
    int i;
    for(i=0;i<M;i++) V.push_back({C[i], A[i], B[i]});
    V.push_back({c, S, E});
    sort(V.begin(),V.end());
    UnionFind UF(N);
    vector<vector<P>> adj;
    adj.resize(N);
    for(i=0;i<V.size();i++) {
        auto it = V[i];
        if(it[0]==c&&UF.Find(S)==UF.Find(E)) return 0;
        if(UF.Find(it[1])==UF.Find(it[2])) continue;
        UF.Merge(it[1], it[2]);
        adj[it[1]].push_back(P(it[2], it[0]));
        adj[it[2]].push_back(P(it[1], it[0]));
    }
    dfs(0, -1, adj);
    long long int ans = min(dis[S], dis[E]) * (c+p)/2;
    return ans;
}
signed main() {
    cin.sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int K;
    cin >> N >> M >> K;
    int i, j;
    for(i=0;i<M;i++) {
        cin >> A[i] >> B[i] >> C[i];
        A[i]--;
        B[i]--;
        C[i] *= 2;
    }
    cin >> S >> E;
    S--;
    E--;
    for(i=0;i<N;i++) cin >> D[i];
    long long int ma = 0;
    for(i=0;i<N;i++) {
        ma = max(get_ans(C[i]+1, -1), ma);
        ma = max(get_ans(C[i]-1, +1), ma);
    }
    cout << ma << '\n';
}

Compilation message (stderr)

toll.cpp: In function 'long long int get_ans(int, int)':
toll.cpp:46:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<long long int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |     for(i=0;i<V.size();i++) {
      |             ~^~~~~~~~~
toll.cpp: In function 'int main()':
toll.cpp:64:12: warning: unused variable 'j' [-Wunused-variable]
   64 |     int i, j;
      |            ^

• Subtask 1: 0 / 16
• Subtask 2: 0 / 18
• Subtask 3: 0 / 22
• Subtask 4: 0 / 22
• Subtask 5: 0 / 22