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Submission #171816

# Submission time Handle Problem Language Result Execution time Memory
171816 2019-12-30T12:51:31 Z VEGAnn Marriage questions (IZhO14_marriage) C++14
70 / 100
 1500 ms 6684 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){

//    for (int it = 0; it < sz(edges); it += 2){
//        edge u = edges[it];
//        if (bad(l, r, u.x) || bad(l, r, u.y)) continue;
//        edges[it].flow = 0;
//        edges[it ^ 1].flow = 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++){
        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
70.0 / 100.0

# 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 376 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 380 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 376 KB Output is correct
14 Correct 2 ms 376 KB Output is correct
15 Correct 2 ms 376 KB Output is correct
16 Correct 2 ms 376 KB Output is correct
17 Correct 2 ms 380 KB Output is correct
18 Correct 2 ms 376 KB Output is correct
19 Correct 11 ms 632 KB Output is correct
20 Correct 4 ms 376 KB Output is correct
21 Correct 3 ms 376 KB Output is correct
22 Correct 2 ms 504 KB Output is correct
23 Correct 4 ms 504 KB Output is correct
24 Correct 3 ms 504 KB Output is correct
25 Correct 221 ms 1212 KB Output is correct
26 Correct 30 ms 632 KB Output is correct
27 Correct 4 ms 504 KB Output is correct
28 Correct 4 ms 504 KB Output is correct
29 Correct 31 ms 1196 KB Output is correct
30 Correct 26 ms 1204 KB Output is correct
31 Execution timed out 1562 ms 3228 KB Time limit exceeded
32 Correct 161 ms 836 KB Output is correct
33 Correct 24 ms 504 KB Output is correct
34 Correct 35 ms 760 KB Output is correct
35 Correct 914 ms 5916 KB Output is correct
36 Correct 700 ms 5912 KB Output is correct
37 Runtime error 3 ms 632 KB Execution killed with signal 11 (could be triggered by violating memory limits)
38 Runtime error 22 ms 6684 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 632 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 5 ms 888 KB Execution killed with signal 11 (could be triggered by violating memory limits)
45 Runtime error 2 ms 632 KB Execution killed with signal 11 (could be triggered by violating memory limits)
46 Runtime error 2 ms 636 KB Execution killed with signal 11 (could be triggered by violating memory limits)
47 Runtime error 2 ms 632 KB Execution killed with signal 11 (could be triggered by violating memory limits)
48 Runtime error 2 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)