Submission #43696

#	Time	Username	Problem	Language	Result	Execution time	Memory
43696		spencercompton	Toll (APIO13_toll)	C++14	16 / 100	4 ms	2856 KiB

toll

#include <bits/stdc++.h>
using namespace std;
int n, m, k;
int numCosts;
class Edge{
    public:
        int s, e, c;
        bool og;
        Edge(int a, int b, int d){
            s = a;
            e = b;
            c = d;
        }
        bool operator<(const Edge &o) const{
            return c<o.c;
        }
};
vector<Edge> options[20];
int use[20];
vector<Edge> used;
long long ans;
vector<Edge> adj[100000];
vector<int> freq;
pair<long long, long long> go2(int now, int from){
    pair<long long, long long> ret = make_pair(freq[now],0LL);
    for(int i = 0; i<adj[now].size(); i++){
        Edge ed = adj[now][i];
        if(ed.e==from){
            continue;
        }
        pair<long long, long long> got = go2(ed.e,now);
        //first sub, second ans
        ret.second += got.second + (long long)got.first*(long long)ed.c;
        ret.first += got.first;
    }
    return ret;
}
void go(int now){
    if(now==numCosts){
        for(int i = 0; i<used.size(); i++){
            adj[used[i].s].push_back(Edge(0,used[i].e,0));
            adj[used[i].e].push_back(Edge(0,used[i].s,0));
        }
        for(int i = 0; i<numCosts; i++){
            Edge ed = options[i][use[i]];
            adj[ed.s].push_back(Edge(0,ed.e,ed.c));
            adj[ed.e].push_back(Edge(0,ed.s,ed.c));
        }
        // for(int i = 0; i<n; i++){
        //     cout << i << ":";
        //     for(int j = 0; j<adj[i].size(); j++){
        //         cout << " " << adj[i][j].e;
        //     }
        //     cout << endl;
        // }
        ans = max(ans,go2(0,-1).second);
        for(int i = 0; i<n; i++){
            adj[i].clear();
        }
    }
    else{
        for(int i = 0; i<options[now].size(); i++){
            use[now] = i;
            go(now+1);
        }
    }
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> n >> m >> k;
    vector<Edge> edges;
    for(int i = 0; i<m; i++){
        int a, b, c;
        cin >> a >> b >> c;
        a--;
        b--;
        edges.push_back(Edge(a,b,c));
    }
    sort(edges.begin(),edges.end());
    vector<Edge> other;
    bool assigned[k];
    for(int i = 0; i<k; i++){
        int a, b;
        cin >> a >> b;
        a--;
        b--;
        assigned[i] = false;
        other.push_back(Edge(a,b,-1));
    }
    int comp[n];
    int sz[n];
    vector<int> li[n];
    for(int i = 0; i<n; i++){
        comp[i] = i;
        sz[i] = 1;
        li[i].push_back(i);
    }
    for(int i = 0; i<m; i++){
        int ca = comp[edges[i].s];
        int cb = comp[edges[i].e];
        if(ca==cb){
            continue;
        }
        if(sz[ca]>sz[cb]){
            swap(ca,cb);
        }
        //ca < cb
        sz[cb] += sz[ca];
        for(int j = 0; j<li[ca].size(); j++){
            comp[li[ca][j]] = cb;
            li[cb].push_back(li[ca][j]);
        }
        li[ca].clear();
        bool any = false;
        for(int j = 0; j<k; j++){
            if(!assigned[j] && comp[other[j].s]==comp[other[j].e]){
                assigned[j] = true;
                any = true;
                other[j].og = false;
                other[j].c = edges[i].c;
            }
        }
        if(!any){
            used.push_back(edges[i]);
        }
        else{
            edges[i].og = true;
            other.push_back(edges[i]);
        }
    }
    for(int i = 0; i<k; i++){
        assert(assigned[i]);
    }
    sort(other.begin(),other.end());
    vector<int> costs;
    numCosts = 0;
    for(int i = 0; i<other.size(); i++){
        if(i==0 || costs[costs.size()-1]!=other[i].c){
            costs.push_back(other[i].c);
            numCosts++;
        }
        if(other[i].og){
            other[i].c = 0;
        }
        options[numCosts-1].push_back(other[i]);
    }
    for(int i = 0; i<n; i++){
        int x;
        cin >> x;
        freq.push_back(x);
    }
    ans = 0LL;
    go(0);
    cout << ans << endl;
    return 0;
}

Compilation message (stderr)

toll.cpp: In function 'std::pair<long long int, long long int> go2(int, int)':
toll.cpp:26:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i<adj[now].size(); i++){
                     ^
toll.cpp: In function 'void go(int)':
toll.cpp:40:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i = 0; i<used.size(); i++){
                         ^
toll.cpp:62:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i = 0; i<options[now].size(); i++){
                         ^
toll.cpp: In function 'int main()':
toll.cpp:110:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j = 0; j<li[ca].size(); j++){
                         ^
toll.cpp:138:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i<other.size(); i++){
                     ^

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