Submission #1125072

#	Time	Username	Problem	Language	Result	Execution time	Memory
1125072		Zero_OP	Restore Array (RMI19_restore)	C++20	100 / 100	284 ms	808 KiB

restore

#include <bits/stdc++.h>

using namespace std;

const int MAX = 1e4 + 5;

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);

#ifdef LOCAL
    freopen("task.inp", "r", stdin);
    freopen("task.out", "w", stdout);
#endif // LOCAL

    int N, M;
    cin >> N >> M;

    vector<tuple<int, int, int>> edges;
    //let pref[i] = number of zeros in prefix 1...i
    for(int i = 0; i < M; ++i){
        int l, r, k, v;
        cin >> l >> r >> k >> v;
        ++r;

        if(v == 0){
            //pref[r] - pref[l] >= k <=> pref[l] - pref[r] <= -k
             edges.emplace_back(l, r, -k);
        } else{
            //pref[r] - pref[l] <= k - 1
            edges.emplace_back(r, l, k - 1);
        }
    }

    for(int i = 0; i < N; ++i){
        //pref[i + 1] - pref[i] <= 1
        edges.emplace_back(i + 1, i, 1);
        //pref[i + 1] - pref[i] >= 0 <=> pref[i] - pref[i + 1] <= 0
        edges.emplace_back(i, i + 1, 0);
    }

    const int inf = 1e9;
    vector<int> f(N + 1, inf);

    f[0] = 0;
    for(int rep = 0; rep < N; ++rep){
        for(auto [u, v, w] : edges){
            if(f[v] > f[u] + w){
                f[v] = f[u] + w;
            }
        }
    }

    for(auto [u, v, w] : edges){
        if(f[v] > f[u] + w){ //negative cycle
            cout << -1 << '\n';
            return 0;
        }
    }

    for(int i = 0; i < N; ++i){
        cout << (f[i + 1] - f[i] < 0 ? 0 : 1) << ' ';
    }

    return 0;
}

/*

Model :
We have a weighted graph G = (V, E)
Where |V| = N + 1, |E| = 2 * N + M
The edge (u, v, w) in the graph represent a constraint that value of a[u] - a[v] <= w
<=> a[u] - w <= a[v] (Look like a shortest path from a start to vertex v ?)
Here a[u] = pref[u] means the number of zeros in 1...u
so which means a[0] = pref[0] = 0
No solution when : exist a negative cycle in the graph

*/

• Subtask 1: 7 / 7
• Subtask 2: 13 / 13
• Subtask 3: 25 / 25
• Subtask 4: 55 / 55