oj.uz

Submission #96042

# Submission time Handle Problem Language Result Execution time Memory
96042 2019-02-05T11:23:44 Z Kastanda Marriage questions (IZhO14_marriage) C++11
96 / 100
 1500 ms 9116 KB 
#include<bits/stdc++.h>
#define pb push_back
using namespace std;
const int MAXN = 34004;
struct Edge {int to, flow;};
int s, t, P[MAXN], D[MAXN], qu[MAXN];
vector < int > Adj[MAXN];
vector < Edge > E;
int ptr, mm;
inline void AddEdge(int v, int u, int w)
{
    Adj[v].pb(E.size());
    E.pb({u, w});
    Adj[u].pb(E.size());
    E.pb({v, 0});
}
inline bool BFS()
{
    int l = 0, r = 0;
    memset(D, -1, sizeof(D));
    memset(P, 0, sizeof(P));
    qu[r ++] = s; D[s] = 0;
    while (r - l)
    {
        int v = qu[l ++];
        for (int i = 0; i < (int)Adj[v].size(); i++)
        {
            int id = Adj[v][i];
            if (mm < E[id].to && E[id].to <= ptr)
                swap(Adj[v][i], Adj[v].back()), Adj[v].pop_back(), i --;
            else if (E[id].flow && D[E[id].to] == -1)
            {
                D[E[id].to] = D[v] + 1;
                if (E[id].to == t)
                    return (1);
                qu[r ++] = E[id].to;
            }
        }
    }
    return (0);
}
int DFS(int v, int flow)
{
    if (v == t)
        return (flow);
    int Flow = 0;
    for (int i = P[v]; i < (int)Adj[v].size(); i++)
    {
        int id = Adj[v][i];
        if (E[id].flow && D[E[id].to] == D[v] + 1)
        {
            int _flow = DFS(E[id].to, min(flow, E[id].flow));
            if (!_flow)
                swap(Adj[v][i], Adj[v][P[v]]), P[v] ++;
            E[id].flow -= _flow;
            E[id^1].flow += _flow;
            Flow += _flow; flow -= _flow;
            if (!flow) return (Flow);
        }
        else
            swap(Adj[v][i], Adj[v][P[v]]), P[v] ++;
    }
    return (Flow);
}
inline int MaxFlow()
{
    int Flow = 0;
    while (BFS())
        Flow += DFS(s, INT_MAX);
    return Flow;
}
int n, m, k;
vector < int > vec[MAXN];
inline void Add(int v)
{
    AddEdge(v + m, t, 1);
    for (int &u : vec[v])
        AddEdge(u, v + m, 1);
}
inline int Del(int v)
{
    v += m;
    for (int &id : Adj[v])
        if (E[id].to == t)
        {
            if (E[id^1].flow == 1)
            {
                int e = -1;
                for (int &idd : Adj[v])
                    if (E[idd].flow)
                        {e = idd; break;}
                assert(e != -1);
                int u = E[e].to;
                E[e].flow -= 1;
                E[e^1].flow += 1;
                E[id^1].flow = 0;
                for (int &idd : Adj[u])
                    if (E[idd].to == s)
                    {
                        E[idd].flow = 0;
                        E[idd^1].flow = 1;
                        return (1);
                    }
                assert(0);

            }
            else
                {E[id].flow = 0; return (0);}
        }
    assert(0);
}
int main()
{
    scanf("%d%d%d", &n, &m, &k);
    int source = 0, sink = n + m + 1;
    s = source; t = sink;
    for (int i = 1; i <= m; i++)
        AddEdge(source, i, 1);
    for (int i = 1; i <= k; i++)
    {
        int v, u;
        scanf("%d%d", &v, &u);
        vec[v].pb(u);
        //AddEdge(u, v + m, 1);
    }
    srand(time(0));
    for (int i = 1; i <= n; i++)
        random_shuffle(vec[i].begin(), vec[i].end());

    int r = 0, Flow = 0;
    int tot = 0;
    ptr = mm = m;
    for (int l = 1; l <= n; l ++)
    {
        while (r < l)
            r ++, Add(r);
        Flow += MaxFlow();
        while (r < n && Flow < m)
            r ++, Add(r), Flow += MaxFlow();
        if (Flow < m)
            break;
        tot += n - r + 1;
        Flow -= Del(l);
        ptr ++;
    }
    return !printf("%d\n", tot);
}

Compilation message

marriage.cpp: In function 'int main()':
marriage.cpp:114:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d", &n, &m, &k);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~
marriage.cpp:122:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &v, &u);
         ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
96.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2168 KB Output is correct
2 Correct 4 ms 2168 KB Output is correct
3 Correct 3 ms 2168 KB Output is correct
4 Correct 4 ms 2168 KB Output is correct
5 Correct 4 ms 2168 KB Output is correct
6 Correct 4 ms 2168 KB Output is correct
7 Correct 4 ms 2216 KB Output is correct
8 Correct 3 ms 2168 KB Output is correct
9 Correct 3 ms 2168 KB Output is correct
10 Correct 3 ms 2172 KB Output is correct
11 Correct 3 ms 2168 KB Output is correct
12 Correct 3 ms 2168 KB Output is correct
13 Correct 3 ms 2168 KB Output is correct
14 Correct 4 ms 2168 KB Output is correct
15 Correct 4 ms 2168 KB Output is correct
16 Correct 3 ms 2168 KB Output is correct
17 Correct 4 ms 2168 KB Output is correct
18 Correct 3 ms 2168 KB Output is correct
19 Correct 9 ms 2424 KB Output is correct
20 Correct 8 ms 2168 KB Output is correct
21 Correct 6 ms 2168 KB Output is correct
22 Correct 6 ms 2172 KB Output is correct
23 Correct 7 ms 2296 KB Output is correct
24 Correct 6 ms 2296 KB Output is correct
25 Correct 42 ms 2784 KB Output is correct
26 Correct 26 ms 2296 KB Output is correct
27 Correct 12 ms 2296 KB Output is correct
28 Correct 15 ms 2296 KB Output is correct
29 Correct 16 ms 2680 KB Output is correct
30 Correct 16 ms 2680 KB Output is correct
31 Correct 388 ms 3824 KB Output is correct
32 Correct 57 ms 2552 KB Output is correct
33 Correct 26 ms 2296 KB Output is correct
34 Correct 39 ms 2404 KB Output is correct
35 Correct 370 ms 5504 KB Output is correct
36 Correct 259 ms 5552 KB Output is correct
37 Correct 1160 ms 4120 KB Output is correct
38 Correct 101 ms 5848 KB Output is correct
39 Correct 542 ms 3316 KB Output is correct
40 Correct 336 ms 3188 KB Output is correct
41 Correct 513 ms 3568 KB Output is correct
42 Correct 294 ms 4188 KB Output is correct
43 Correct 272 ms 5828 KB Output is correct
44 Correct 402 ms 5836 KB Output is correct
45 Correct 972 ms 5156 KB Output is correct
46 Execution timed out 1561 ms 6864 KB Time limit exceeded
47 Correct 706 ms 9116 KB Output is correct
48 Correct 715 ms 6788 KB Output is correct
49 Execution timed out 1574 ms 6488 KB Time limit exceeded
50 Correct 1404 ms 4720 KB Output is correct