Submission #91394

# Submission time Handle Problem Language Result Execution time Memory
91394 2018-12-27T10:41:33 Z mirbek01 Marriage questions (IZhO14_marriage) C++11
78 / 100
1500 ms 12464 KB
# include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 2;

int n, m, k, mt[N], used[N], ans, L, R;
vector <int> g[N], vr, mr;

bool dfs(int v){
      if(used[v])
            return 0;
      vr.push_back(v);
      used[v] = 1;
      for(int to : g[v]){
            if(to <= n && (to > R || to < L))
                  continue;
            if(mt[to] == -1 || dfs(mt[to])){
                  mt[to] = v;
                  mt[v] = to;
                  return true;
            }
      }
      return false;
}

bool check(){
      if(mt[L] == -1)
            return true;
      vector <int> dl;
      while(!mr.empty()){
            int v = mr.back();
            if(mt[v] == -1){
                  for(int i = 0; i < vr.size(); i ++){
                        used[vr[i]] = 0;
                  }
                  if(!dfs(v)){
                        for(int j = 0; j < (int)dl.size(); j ++)
                              mr.push_back(dl[j]);
                        return false;
                  }
            }
            mr.pop_back();
            dl.push_back(v);
      }
      return mr.empty();
}

bool ok(){
      for(int i = n + 1; i <= n + m; i ++){
            if(mt[i] != -1){
                  mt[ mt[i] ] = -1;
                  mt[i] = -1;
            }
      }
      for(int i = n + 1; i <= n + m; i ++){
            for(int j = 0; j < (int)vr.size(); j ++){
                  used[ vr[j] ] = 0;
            }
            vr.clear();
            dfs(i);
      }
      for(int i = n + 1; i <= n + m; i ++){
            if(mt[i] == -1)
                  return false;
      }
      return true;
}

int main(){
      scanf("%d %d %d", &n, &m, &k);

      for(int i = 1; i <= k; i ++){
            int a, b;
            scanf("%d %d", &a, &b);
            g[a].push_back(b + n);
            g[b + n].push_back(a);
      }

      for(int i = 1; i <= n + m; i ++){
            sort(g[i].begin(), g[i].end());
      }

      memset(mt, -1, sizeof(mt));

      int lo = 1, hi = n + 1;

      L = 1;

      while(lo < hi){
            int md = (lo + hi) >> 1;
            R = md;
            if(ok())
                  hi = md;
            else
                  lo = md + 1;
      }

      if(lo > n){
            cout << 0 << endl;
            return 0;
      }

      ans += n - lo + 1;

      R = lo;
      ok();

      if(mt[L] != -1){
            mt[mt[L]] = -1;
            mr.push_back(mt[L]);
      }

      int pt = lo;

      for(int i = 2; i <= n; i ++){
            L = i, R = pt;
            while(pt <= n && !check())
                  pt ++, R = pt;
            ans += n - pt + 1;
            if(mt[L] != -1){
                  mt[mt[L]] = -1;
                  mr.push_back(mt[L]);
            }
      }

      printf("%d", ans);
}

Compilation message

marriage.cpp: In function 'bool check()':
marriage.cpp:34:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                   for(int i = 0; i < vr.size(); i ++){
                                  ~~^~~~~~~~~~~
marriage.cpp: In function 'int main()':
marriage.cpp:71:12: 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:75:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d %d", &a, &b);
             ~~~~~^~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 3 ms 3064 KB Output is correct
2 Incorrect 4 ms 3188 KB Output isn't correct
3 Incorrect 3 ms 3188 KB Output isn't correct
4 Correct 3 ms 3316 KB Output is correct
5 Correct 3 ms 3316 KB Output is correct
6 Correct 4 ms 3316 KB Output is correct
7 Correct 3 ms 3316 KB Output is correct
8 Correct 3 ms 3316 KB Output is correct
9 Correct 3 ms 3316 KB Output is correct
10 Correct 3 ms 3316 KB Output is correct
11 Correct 4 ms 3316 KB Output is correct
12 Correct 3 ms 3316 KB Output is correct
13 Incorrect 3 ms 3424 KB Output isn't correct
14 Correct 3 ms 3424 KB Output is correct
15 Correct 3 ms 3424 KB Output is correct
16 Correct 3 ms 3424 KB Output is correct
17 Correct 4 ms 3424 KB Output is correct
18 Correct 3 ms 3424 KB Output is correct
19 Correct 5 ms 3424 KB Output is correct
20 Correct 4 ms 3424 KB Output is correct
21 Correct 3 ms 3424 KB Output is correct
22 Correct 4 ms 3424 KB Output is correct
23 Correct 4 ms 3424 KB Output is correct
24 Correct 4 ms 3424 KB Output is correct
25 Correct 41 ms 4088 KB Output is correct
26 Incorrect 14 ms 4088 KB Output isn't correct
27 Correct 4 ms 4088 KB Output is correct
28 Correct 5 ms 4088 KB Output is correct
29 Correct 6 ms 4088 KB Output is correct
30 Correct 5 ms 4088 KB Output is correct
31 Correct 383 ms 6148 KB Output is correct
32 Correct 13 ms 6148 KB Output is correct
33 Correct 4 ms 6148 KB Output is correct
34 Correct 26 ms 6148 KB Output is correct
35 Correct 182 ms 6148 KB Output is correct
36 Correct 140 ms 6148 KB Output is correct
37 Execution timed out 1566 ms 12464 KB Time limit exceeded
38 Correct 30 ms 12464 KB Output is correct
39 Execution timed out 1577 ms 12464 KB Time limit exceeded
40 Correct 8 ms 12464 KB Output is correct
41 Incorrect 159 ms 12464 KB Output isn't correct
42 Correct 12 ms 12464 KB Output is correct
43 Correct 17 ms 12464 KB Output is correct
44 Correct 26 ms 12464 KB Output is correct
45 Incorrect 208 ms 12464 KB Output isn't correct
46 Execution timed out 1569 ms 12464 KB Time limit exceeded
47 Correct 30 ms 12464 KB Output is correct
48 Correct 28 ms 12464 KB Output is correct
49 Execution timed out 1569 ms 12464 KB Time limit exceeded
50 Execution timed out 1572 ms 12464 KB Time limit exceeded