Submission #171819

# Submission time Handle Problem Language Result Execution time Memory
171819 2019-12-30T12:54:14 Z VEGAnn Marriage questions (IZhO14_marriage) C++14
72 / 100
675 ms 6556 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 = 2000;
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;
}
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 380 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 2 ms 376 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 2 ms 376 KB Output is correct
13 Correct 2 ms 428 KB Output is correct
14 Correct 2 ms 248 KB Output is correct
15 Correct 2 ms 380 KB Output is correct
16 Correct 2 ms 376 KB Output is correct
17 Correct 2 ms 376 KB Output is correct
18 Correct 2 ms 380 KB Output is correct
19 Correct 6 ms 632 KB Output is correct
20 Correct 3 ms 504 KB Output is correct
21 Correct 2 ms 376 KB Output is correct
22 Correct 2 ms 376 KB Output is correct
23 Correct 3 ms 504 KB Output is correct
24 Correct 3 ms 376 KB Output is correct
25 Correct 100 ms 1212 KB Output is correct
26 Correct 23 ms 632 KB Output is correct
27 Correct 3 ms 504 KB Output is correct
28 Correct 4 ms 504 KB Output is correct
29 Correct 29 ms 1196 KB Output is correct
30 Correct 23 ms 1204 KB Output is correct
31 Correct 675 ms 3260 KB Output is correct
32 Correct 34 ms 888 KB Output is correct
33 Correct 13 ms 504 KB Output is correct
34 Correct 22 ms 632 KB Output is correct
35 Correct 320 ms 5784 KB Output is correct
36 Correct 217 ms 6012 KB Output is correct
37 Runtime error 3 ms 696 KB Execution killed with signal 11 (could be triggered by violating memory limits)
38 Runtime error 22 ms 6556 KB Execution killed with signal 11 (could be triggered by violating memory limits)
39 Runtime error 3 ms 632 KB Execution killed with signal 11 (could be triggered by violating memory limits)
40 Runtime error 3 ms 604 KB Execution killed with signal 11 (could be triggered by violating memory limits)
41 Runtime error 3 ms 632 KB Execution killed with signal 11 (could be triggered by violating memory limits)
42 Runtime error 4 ms 1144 KB Execution killed with signal 11 (could be triggered by violating memory limits)
43 Runtime error 4 ms 1144 KB Execution killed with signal 11 (could be triggered by violating memory limits)
44 Runtime error 6 ms 760 KB Execution killed with signal 11 (could be triggered by violating memory limits)
45 Runtime error 3 ms 552 KB Execution killed with signal 11 (could be triggered by violating memory limits)
46 Runtime error 3 ms 632 KB Execution killed with signal 11 (could be triggered by violating memory limits)
47 Runtime error 3 ms 652 KB Execution killed with signal 11 (could be triggered by violating memory limits)
48 Runtime error 4 ms 632 KB Execution killed with signal 11 (could be triggered by violating memory limits)
49 Runtime error 3 ms 632 KB Execution killed with signal 11 (could be triggered by violating memory limits)
50 Runtime error 3 ms 632 KB Execution killed with signal 11 (could be triggered by violating memory limits)