oj.uz

Submission #171841

# Submission time Handle Problem Language Result Execution time Memory
171841 2019-12-30T13:23:46 Z VEGAnn Marriage questions (IZhO14_marriage) C++14
80 / 100
 1500 ms 7652 KB 
#include <bits/stdc++.h>
#define sz(x) ((int)x.size())
#define PB push_back
#define MP make_pair
#define y first
#define psh second
#define edge pair<int, bool>
#define pi3 pair<pii, int>
#define MP3(a,b,c) MP(MP(a, b), c)
using namespace std;
const int oo = 1e9;
const int N = 32100;
const int K = 110;
const int PW = 20;

vector<edge> edges;
queue<int> q;
vector<int> g[N];
int ans = 0, s, t, n, m, k, dst[N], ptr[N];

void add_edge(int x, int y){

    g[x].PB(sz(edges));
    edges.PB(edge(y, 0));

    g[y].PB(sz(edges));
    edges.PB(edge(x, 1));

}

bool bad(int l, int r, int v){
    if (v == s || v == t || v < m) return 0;
    return !(m + l <= v && v <= m + r);
}

bool bfs(int l, int r){
    fill(dst, dst + t + 1, oo);

    dst[s] = 0;
    while (sz(q)) q.pop();
    q.push(s);

    while (sz(q)){
        int v = q.front(); q.pop();

        for (int nm : g[v]){
            edge u = edges[nm];
            if (!bad(l, r, u.y) && !u.psh && dst[u.y] > dst[v] + 1){
                dst[u.y] = dst[v] + 1;
                q.push(u.y);
            }
        }
    }

    return (dst[t] < oo);
}

bool dfs(int v, bool pshd){
    if (pshd == 0) return 0;
    if (v == t) return pshd;
    for (; ptr[v] < sz(g[v]); ptr[v]++){
        int nm = g[v][ptr[v]];
        edge u = edges[nm];
        if (dst[u.y] != dst[v] + 1) continue;
        int nw = dfs(u.y, min(pshd, !u.psh));
        if (nw){
            edges[nm].psh = 1;
            edges[nm ^ 1].psh = 0;
            return nw;
        }
    }
    return 0;
}

bool ok(int l, int r){

    if (r - l + 1 < m) return 0;

    int flow = 0;

    for (int i = 0; i < m; i++) {
        int nm = g[s][i];
        flow += edges[nm].psh;
    }

    while (bfs(l, r)){
        fill(ptr, ptr + t + 1, 0);
        int pshd = dfs(s, oo);
        while (pshd > 0){
            flow += pshd;
            pshd = dfs(s, oo);
        }
    }

    return (flow == m);
}

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

    cin >> n >> m >> k;

    for (int i = 0; i < k; i++){
        int x, y; cin >> y >> x;
        x--; y--;
        add_edge(x, m + y);
    }

    s = n + m;
    t = n + m + 1;

    for (int i = 0; i < m; i++)
        add_edge(s, i);

    for (int i = 0; i < n; i++)
        add_edge(i + m, t);

    for (int l = 0, r = 0; l < n; l++){

        if (l + m - 1 >= n) break;

        while (r < n && !ok(l, r))
            r++;
        if (r >= n) break;
        ans += n - r;

        int nm = g[t][l];

        if (edges[nm].psh) continue;

        int pr = -1, cr = m + l;
        for (int it = 0; it < sz(g[cr]); it++){
            int nm = g[cr][it];
            edge ed = edges[nm];

            if (ed.y != t && !ed.psh){
                pr = ed.y;
                break;
            }
        }

        nm = g[s][pr];
        edges[nm].psh = 0;
        edges[nm ^ 1].psh = 1;
    }

    cout << ans;

    return 0;
}

Subtask #1
80.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 1144 KB Output is correct
2 Correct 3 ms 1144 KB Output is correct
3 Correct 3 ms 1016 KB Output is correct
4 Correct 3 ms 1016 KB Output is correct
5 Correct 3 ms 1016 KB Output is correct
6 Correct 2 ms 1016 KB Output is correct
7 Correct 3 ms 1016 KB Output is correct
8 Correct 3 ms 1016 KB Output is correct
9 Correct 3 ms 1016 KB Output is correct
10 Correct 3 ms 1144 KB Output is correct
11 Correct 3 ms 1144 KB Output is correct
12 Correct 3 ms 1016 KB Output is correct
13 Correct 3 ms 1144 KB Output is correct
14 Correct 3 ms 1144 KB Output is correct
15 Correct 3 ms 1016 KB Output is correct
16 Correct 3 ms 1148 KB Output is correct
17 Correct 3 ms 1016 KB Output is correct
18 Correct 3 ms 1016 KB Output is correct
19 Correct 4 ms 1144 KB Output is correct
20 Correct 4 ms 1144 KB Output is correct
21 Correct 3 ms 1144 KB Output is correct
22 Correct 4 ms 1144 KB Output is correct
23 Correct 3 ms 1144 KB Output is correct
24 Correct 3 ms 1016 KB Output is correct
25 Correct 78 ms 1660 KB Output is correct
26 Correct 21 ms 1272 KB Output is correct
27 Correct 4 ms 1116 KB Output is correct
28 Correct 4 ms 1144 KB Output is correct
29 Correct 22 ms 1528 KB Output is correct
30 Correct 18 ms 1528 KB Output is correct
31 Correct 583 ms 2520 KB Output is correct
32 Correct 26 ms 1400 KB Output is correct
33 Correct 12 ms 1272 KB Output is correct
34 Correct 18 ms 1272 KB Output is correct
35 Correct 266 ms 3872 KB Output is correct
36 Correct 180 ms 3920 KB Output is correct
37 Execution timed out 1532 ms 2664 KB Time limit exceeded
38 Correct 364 ms 4464 KB Output is correct
39 Correct 717 ms 2100 KB Output is correct
40 Correct 722 ms 2164 KB Output is correct
41 Execution timed out 1543 ms 2484 KB Time limit exceeded
42 Correct 1112 ms 2988 KB Output is correct
43 Execution timed out 1525 ms 4588 KB Time limit exceeded
44 Execution timed out 1516 ms 4644 KB Time limit exceeded
45 Execution timed out 1559 ms 4108 KB Time limit exceeded
46 Execution timed out 1555 ms 5604 KB Time limit exceeded
47 Execution timed out 1567 ms 7524 KB Time limit exceeded
48 Execution timed out 1558 ms 5484 KB Time limit exceeded
49 Execution timed out 1572 ms 7652 KB Time limit exceeded
50 Execution timed out 1564 ms 3308 KB Time limit exceeded