Submission #4025957

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Source Code Expand

#include <iostream>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>

static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using namespace std;

template<class T>
constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;

template<class T>
class Dinic {
    struct edge {
        int to{}, rev{};
        T cap;
        edge() = default;
        edge(int to, T cap, int rev):to(to), cap(cap), rev(rev) {}
    };
    int n{};
    vector<vector<edge>> G;
    vector<int> level, iter;
public:
    Dinic() = default;
    explicit Dinic(int sz): n(sz), G(n), level(n), iter(n){}
    void add_edge(int from, int to, T cap){
        G[from].emplace_back(to, cap, G[to].size());
        G[to].emplace_back(from, 0, G[from].size()-1);
    }

    void bfs(int s){
        fill(level.begin(), level.end(), -1);
        queue<int> Q;
        level[s] = 0;
        Q.emplace(s);
        while(!Q.empty()){
            int v = Q.front(); Q.pop();
            for (auto &&e : G[v]) {
                if(e.cap > 0 && level[e.to] < 0){
                    level[e.to] = level[v]+1;
                    Q.emplace(e.to);
                }
            }
        }
    }

    T dfs(int v, int t, T f){
        if(v == t) return f;
        for (int &i = iter[v]; i < G[v].size(); ++i) {
            edge &e = G[v][i];
            if(e.cap > 0 && level[v] < level[e.to]){
                T d = dfs(e.to, t, min(f, e.cap));
                if(d > 0){
                    e.cap -= d;
                    G[e.to][e.rev].cap += d;
                    return d;
                }
            }
        }
        return 0;
    }

    T flow(int s, int t, T lim = INF<T>){
        T fl = 0;
        while(true){
            bfs(s);
            if(level[t] < 0 || lim == 0) return fl;
            fill(iter.begin(), iter.end(), 0);
            T f;
            while((f=dfs(s,t, lim))>0){
                fl += f;
                lim -= f;
            }
        }
    }

    bool back_edge(int s, int t, int from, int to){
        for (auto &&e : G[from]) {
            if(e.to == to) {
                if(e.cap == 0 && flow(from, to, 1) == 0){
                    flow(from, s, 1);
                    flow(t, to, 1);
                    return true;
                }
            }
        }
        return false;
    }

};

int main() {
    int n;
    cin >> n;
    vector<ll> v(n);
    for (auto &&i : v) scanf("%lld", &i);
    Dinic<ll> fl(n+2);
    ll ans = 0;
    for (int i = 0; i < n; ++i) {
        if(v[i] >= 0){
            fl.add_edge(0, i+1, 0);
            fl.add_edge(i+1, n+1, v[i]);
            ans += v[i];
        }else {
            fl.add_edge(0, i+1, -v[i]);
            fl.add_edge(i+1, n+1, 0);
        }
    }
    for (int i = 0; i < n; ++i) {
        if(v[i] == 0) continue;
        for (int j = 0; j < n; ++j) {
            if(i == j) continue;
            if((j+1)%(i+1) == 0) {
                fl.add_edge(i+1, j+1, 1000LL*MOD);
            }
        }
    }
    cout << ans-fl.flow(0, n+1) << "\n";
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:103:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     for (auto &&i : v) scanf("%lld", &i);
                                         ^

Judge Result