oj.uz

Submission #171821

# Submission time Handle Problem Language Result Execution time Memory
171821 2019-12-30T12:54:58 Z VEGAnn Marriage questions (IZhO14_marriage) C++14
80 / 100
 1500 ms 12320 KB 
#include <bits/stdc++.h>
#define sz(x) ((int)x.size())
#define PB push_back
#define MP make_pair
#define ft first
#define sd second
#define pii pair<int, int>
#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;

struct edge{
    int x, y, cap, flow;

    edge(int _x, int _y, int _c, int _f): x(_x), y(_y), cap(_c), flow(_f) {}
};

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, int cap){

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

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

}

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.cap > u.flow && dst[u.y] > dst[v] + 1){
                dst[u.y] = dst[v] + 1;
                q.push(u.y);
            }
        }
    }

    return (dst[t] < oo);
}

int dfs(int v, int 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.cap - u.flow));
        if (nw){
            edges[nm].flow += nw;
            edges[nm ^ 1].flow -= nw;
            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 += bool(edges[nm].cap == edges[nm].flow);
    }

    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, 1);
    }

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

    for (int i = 0; i < m; i++)
        add_edge(s, i, 1);

    for (int i = 0; i < n; i++)
        add_edge(i + m, t, 1);

    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].cap == edges[nm].flow) 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.cap > ed.flow){
                pr = ed.y;
                break;
            }
        }

        nm = g[s][pr];
        edges[nm].flow--;
        edges[nm ^ 1].flow++;
    }

    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 1144 KB Output is correct
4 Correct 3 ms 1144 KB Output is correct
5 Correct 3 ms 1016 KB Output is correct
6 Correct 3 ms 1016 KB Output is correct
7 Correct 3 ms 1144 KB Output is correct
8 Correct 3 ms 1144 KB Output is correct
9 Correct 3 ms 1144 KB Output is correct
10 Correct 3 ms 1016 KB Output is correct
11 Correct 3 ms 1144 KB Output is correct
12 Correct 3 ms 1144 KB Output is correct
13 Correct 3 ms 1016 KB Output is correct
14 Correct 3 ms 1016 KB Output is correct
15 Correct 3 ms 1144 KB Output is correct
16 Correct 3 ms 1016 KB Output is correct
17 Correct 3 ms 1144 KB Output is correct
18 Correct 3 ms 1144 KB Output is correct
19 Correct 6 ms 1272 KB Output is correct
20 Correct 4 ms 1144 KB Output is correct
21 Correct 3 ms 1144 KB Output is correct
22 Correct 3 ms 1144 KB Output is correct
23 Correct 3 ms 1144 KB Output is correct
24 Correct 3 ms 1144 KB Output is correct
25 Correct 105 ms 1852 KB Output is correct
26 Correct 23 ms 1272 KB Output is correct
27 Correct 4 ms 1144 KB Output is correct
28 Correct 5 ms 1144 KB Output is correct
29 Correct 29 ms 1836 KB Output is correct
30 Correct 24 ms 1844 KB Output is correct
31 Correct 674 ms 3644 KB Output is correct
32 Correct 35 ms 1528 KB Output is correct
33 Correct 13 ms 1272 KB Output is correct
34 Correct 22 ms 1400 KB Output is correct
35 Correct 321 ms 5912 KB Output is correct
36 Correct 216 ms 6040 KB Output is correct
37 Execution timed out 1538 ms 4036 KB Time limit exceeded
38 Correct 526 ms 6172 KB Output is correct
39 Correct 936 ms 2456 KB Output is correct
40 Correct 855 ms 2544 KB Output is correct
41 Execution timed out 1566 ms 2920 KB Time limit exceeded
42 Correct 1423 ms 4032 KB Output is correct
43 Execution timed out 1561 ms 6568 KB Time limit exceeded
44 Execution timed out 1574 ms 6820 KB Time limit exceeded
45 Execution timed out 1545 ms 5064 KB Time limit exceeded
46 Execution timed out 1570 ms 8028 KB Time limit exceeded
47 Execution timed out 1569 ms 12320 KB Time limit exceeded
48 Execution timed out 1571 ms 7868 KB Time limit exceeded
49 Execution timed out 1571 ms 12252 KB Time limit exceeded
50 Execution timed out 1570 ms 4208 KB Time limit exceeded