답안 #135031

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
135031 2019-07-23T14:38:41 Z tmwilliamlin168 Simurgh (IOI17_simurgh) C++14
100 / 100
952 ms 7480 KB
#include "simurgh.h"
#include <bits/stdc++.h>
using namespace std;

#define vi vector<int>
#define pb push_back

const int mN=500, mM=124750;
int n, tin[mN], low[mN], dt=1, b[mM], bs, st[mM], sth, t[mN], p[mN], c[mN];
vi eu, ev, adj[mN], ans;

void dfs1(int u=0, int p=-1) {
	tin[u]=low[u]=dt++;
	for(int e : adj[u]) {
		int v=eu[e]^ev[e]^u;
		if(!tin[v]) {
			st[sth++]=e;
			dfs1(v, u);
			low[u]=min(low[v], low[u]);
			if(low[v]>=tin[u]) {
				do {
					b[st[--sth]]=bs;
				} while(st[sth]^e);
				++bs;
			}
		} else if(v^p&&tin[v]<tin[u]) {
			st[sth++]=e;
			low[u]=min(tin[v], low[u]);
		}
	}
}

int find(int x) {
	return x^p[x]?p[x]=find(p[x]):x;
}

bool join(int x, int y) {
	if((x=find(x))==(y=find(y)))
		return 0;
	p[x]=y;
	return 1;
}

void fst(vi w, vi &r) {
	for(int i=0; i<eu.size(); ++i)
		if(w[i]&&join(eu[i], ev[i]))
			r.pb(i);
}

void dc(vi &a, vi &b, vi &c, int l, int r, int s1, int s2) {
	if(s2==s1)
		return;
	if(l==r) {
		c.pb(b[l]);
		return;
	}
	int m=(l+r)/2;
	vi d=a;
	for(int i=l; i<=m; ++i)
		d[i]=b[i];
	int sl=count_common_roads(d);
	dc(a, b, c, l, m, s1, sl);
	dc(a, b, c, m+1, r, s1, s2-sl+s1);
}

void dfs2(int u=0, int pe=-1) {
	vi v1, v2, r;
	for(int e : adj[u]) {
		int v=eu[e]^ev[e]^u;
		if(c[v])
			continue;
		if(t[v]<0) {
			v2.pb(e);
			t[v]=e;
		} else
			v1.pb(e);
	}
	if(v1.size()) {
		iota(p, p+n, 0);
		vi s1, w(eu.size(), 1), s2=v1;
		for(int i=0; i<v1.size(); ++i) {
			s1.pb(t[eu[v1[i]]^ev[v1[i]]^u]);
			join(eu[s1.back()], ev[s1.back()]);
		}
		for(int e : ans) {
			s1.pb(e);
			join(eu[e], ev[e]);
		}
		for(int e : v1) {
			w[e]=0;
			w[t[eu[e]^ev[e]^u]]=0;
		}
		fst(w, s1);
		s2.insert(s2.end(), s1.begin()+v1.size(), s1.end());
		dc(s1, v1, r, 0, v1.size()-1, count_common_roads(s1), count_common_roads(s2));
	}
	if(v2.size()) {
		vi w(eu.size(), 1), s;
		for(int e : adj[u])
			w[e]=0;
		iota(p, p+n, 0);
		fst(w, s);
		for(int e : r)
			if(join(eu[e], ev[e]))
				s.pb(e);
		if(~pe&&join(eu[pe], ev[pe]))
			s.pb(pe);
		for(int e : adj[u])
			if(join(eu[e], ev[e]))
				s.pb(e);
		int bc=count_common_roads(s);
		sort(v2.begin(), v2.end(), [](const int &i, const int &j) {
			return b[i]<b[j];
		});
		for(int i=0, j=0, o; i<v2.size(); ) {
			for(; j<v2.size()&&b[v2[j]]==b[v2[i]]; ++j);
			for(int e : s)
				if(b[e]==b[v2[i]]&&(eu[e]==u||ev[e]==u))
					o=e;
			s.erase(find(s.begin(), s.end(), o));
			vi a;
			int cm=bc;
			for(; i<j; ++i) {
				s.push_back(v2[i]);
				int cc=count_common_roads(s);
				if(cc>cm) {
					cm=cc;
					a=vector<int>();
				}
				if(cc==cm)
					a.push_back(v2[i]);
				s.pop_back();
			}
			s.push_back(o);
			r.insert(r.end(), a.begin(), a.end());
		}
	}
	for(int e : r) {
		ans.push_back(e);
		c[eu[e]^ev[e]^u]=1;
	}
	for(int e : r)
		dfs2(eu[e]^ev[e]^u, e);
}

vi find_roads(int n, vector<int> u, vector<int> v) {
	::n=n;
	eu=u;
	ev=v;
	for(int i=0; i<u.size(); ++i) {
		adj[u[i]].push_back(i);
		adj[v[i]].push_back(i);
	}
	dfs1();
	c[0]=1;
	memset(t, -1, 4*n);
	dfs2();
	return ans;
}

Compilation message

simurgh.cpp: In function 'void fst(std::vector<int>, std::vector<int>&)':
simurgh.cpp:45:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<eu.size(); ++i)
               ~^~~~~~~~~~
simurgh.cpp: In function 'void dfs2(int, int)':
simurgh.cpp:81:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0; i<v1.size(); ++i) {
                ~^~~~~~~~~~
simurgh.cpp:115:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0, j=0, o; i<v2.size(); ) {
                        ~^~~~~~~~~~
simurgh.cpp:116:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(; j<v2.size()&&b[v2[j]]==b[v2[i]]; ++j);
          ~^~~~~~~~~~
simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:150:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<u.size(); ++i) {
               ~^~~~~~~~~
# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB correct
2 Correct 2 ms 376 KB correct
3 Correct 2 ms 376 KB correct
4 Correct 2 ms 376 KB correct
5 Correct 2 ms 376 KB correct
6 Correct 2 ms 380 KB correct
7 Correct 2 ms 380 KB correct
8 Correct 2 ms 376 KB correct
9 Correct 2 ms 376 KB correct
10 Correct 2 ms 376 KB correct
11 Correct 3 ms 376 KB correct
12 Correct 2 ms 376 KB correct
13 Correct 2 ms 376 KB correct
# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB correct
2 Correct 2 ms 376 KB correct
3 Correct 2 ms 376 KB correct
4 Correct 2 ms 376 KB correct
5 Correct 2 ms 376 KB correct
6 Correct 2 ms 380 KB correct
7 Correct 2 ms 380 KB correct
8 Correct 2 ms 376 KB correct
9 Correct 2 ms 376 KB correct
10 Correct 2 ms 376 KB correct
11 Correct 3 ms 376 KB correct
12 Correct 2 ms 376 KB correct
13 Correct 2 ms 376 KB correct
14 Correct 4 ms 376 KB correct
15 Correct 3 ms 376 KB correct
16 Correct 2 ms 504 KB correct
17 Correct 4 ms 376 KB correct
18 Correct 1 ms 376 KB correct
19 Correct 4 ms 376 KB correct
20 Correct 3 ms 376 KB correct
21 Correct 3 ms 376 KB correct
22 Correct 3 ms 376 KB correct
23 Correct 3 ms 376 KB correct
24 Correct 3 ms 376 KB correct
25 Correct 2 ms 376 KB correct
26 Correct 3 ms 376 KB correct
27 Correct 3 ms 380 KB correct
28 Correct 3 ms 376 KB correct
29 Correct 2 ms 376 KB correct
30 Correct 3 ms 376 KB correct
31 Correct 3 ms 376 KB correct
32 Correct 3 ms 376 KB correct
33 Correct 3 ms 376 KB correct
# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB correct
2 Correct 2 ms 376 KB correct
3 Correct 2 ms 376 KB correct
4 Correct 2 ms 376 KB correct
5 Correct 2 ms 376 KB correct
6 Correct 2 ms 380 KB correct
7 Correct 2 ms 380 KB correct
8 Correct 2 ms 376 KB correct
9 Correct 2 ms 376 KB correct
10 Correct 2 ms 376 KB correct
11 Correct 3 ms 376 KB correct
12 Correct 2 ms 376 KB correct
13 Correct 2 ms 376 KB correct
14 Correct 4 ms 376 KB correct
15 Correct 3 ms 376 KB correct
16 Correct 2 ms 504 KB correct
17 Correct 4 ms 376 KB correct
18 Correct 1 ms 376 KB correct
19 Correct 4 ms 376 KB correct
20 Correct 3 ms 376 KB correct
21 Correct 3 ms 376 KB correct
22 Correct 3 ms 376 KB correct
23 Correct 3 ms 376 KB correct
24 Correct 3 ms 376 KB correct
25 Correct 2 ms 376 KB correct
26 Correct 3 ms 376 KB correct
27 Correct 3 ms 380 KB correct
28 Correct 3 ms 376 KB correct
29 Correct 2 ms 376 KB correct
30 Correct 3 ms 376 KB correct
31 Correct 3 ms 376 KB correct
32 Correct 3 ms 376 KB correct
33 Correct 3 ms 376 KB correct
34 Correct 107 ms 1848 KB correct
35 Correct 106 ms 2068 KB correct
36 Correct 75 ms 1452 KB correct
37 Correct 21 ms 376 KB correct
38 Correct 110 ms 1940 KB correct
39 Correct 86 ms 1692 KB correct
40 Correct 64 ms 1452 KB correct
41 Correct 14 ms 1832 KB correct
42 Correct 14 ms 1912 KB correct
43 Correct 52 ms 1144 KB correct
44 Correct 45 ms 1040 KB correct
45 Correct 50 ms 1016 KB correct
46 Correct 41 ms 888 KB correct
47 Correct 30 ms 632 KB correct
48 Correct 9 ms 376 KB correct
49 Correct 16 ms 504 KB correct
50 Correct 25 ms 632 KB correct
51 Correct 52 ms 1144 KB correct
52 Correct 46 ms 1016 KB correct
53 Correct 45 ms 1016 KB correct
54 Correct 53 ms 1272 KB correct
55 Correct 54 ms 1016 KB correct
56 Correct 54 ms 1144 KB correct
57 Correct 53 ms 1148 KB correct
# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB correct
2 Correct 2 ms 376 KB correct
3 Correct 484 ms 4476 KB correct
4 Correct 938 ms 6692 KB correct
5 Correct 938 ms 6712 KB correct
6 Correct 57 ms 6436 KB correct
7 Correct 236 ms 6476 KB correct
8 Correct 279 ms 6440 KB correct
9 Correct 949 ms 6636 KB correct
10 Correct 939 ms 6972 KB correct
11 Correct 928 ms 6480 KB correct
12 Correct 938 ms 7188 KB correct
13 Correct 2 ms 376 KB correct
14 Correct 533 ms 6628 KB correct
15 Correct 932 ms 7404 KB correct
# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB correct
2 Correct 2 ms 376 KB correct
3 Correct 2 ms 376 KB correct
4 Correct 2 ms 376 KB correct
5 Correct 2 ms 376 KB correct
6 Correct 2 ms 380 KB correct
7 Correct 2 ms 380 KB correct
8 Correct 2 ms 376 KB correct
9 Correct 2 ms 376 KB correct
10 Correct 2 ms 376 KB correct
11 Correct 3 ms 376 KB correct
12 Correct 2 ms 376 KB correct
13 Correct 2 ms 376 KB correct
14 Correct 4 ms 376 KB correct
15 Correct 3 ms 376 KB correct
16 Correct 2 ms 504 KB correct
17 Correct 4 ms 376 KB correct
18 Correct 1 ms 376 KB correct
19 Correct 4 ms 376 KB correct
20 Correct 3 ms 376 KB correct
21 Correct 3 ms 376 KB correct
22 Correct 3 ms 376 KB correct
23 Correct 3 ms 376 KB correct
24 Correct 3 ms 376 KB correct
25 Correct 2 ms 376 KB correct
26 Correct 3 ms 376 KB correct
27 Correct 3 ms 380 KB correct
28 Correct 3 ms 376 KB correct
29 Correct 2 ms 376 KB correct
30 Correct 3 ms 376 KB correct
31 Correct 3 ms 376 KB correct
32 Correct 3 ms 376 KB correct
33 Correct 3 ms 376 KB correct
34 Correct 107 ms 1848 KB correct
35 Correct 106 ms 2068 KB correct
36 Correct 75 ms 1452 KB correct
37 Correct 21 ms 376 KB correct
38 Correct 110 ms 1940 KB correct
39 Correct 86 ms 1692 KB correct
40 Correct 64 ms 1452 KB correct
41 Correct 14 ms 1832 KB correct
42 Correct 14 ms 1912 KB correct
43 Correct 52 ms 1144 KB correct
44 Correct 45 ms 1040 KB correct
45 Correct 50 ms 1016 KB correct
46 Correct 41 ms 888 KB correct
47 Correct 30 ms 632 KB correct
48 Correct 9 ms 376 KB correct
49 Correct 16 ms 504 KB correct
50 Correct 25 ms 632 KB correct
51 Correct 52 ms 1144 KB correct
52 Correct 46 ms 1016 KB correct
53 Correct 45 ms 1016 KB correct
54 Correct 53 ms 1272 KB correct
55 Correct 54 ms 1016 KB correct
56 Correct 54 ms 1144 KB correct
57 Correct 53 ms 1148 KB correct
58 Correct 2 ms 376 KB correct
59 Correct 2 ms 376 KB correct
60 Correct 484 ms 4476 KB correct
61 Correct 938 ms 6692 KB correct
62 Correct 938 ms 6712 KB correct
63 Correct 57 ms 6436 KB correct
64 Correct 236 ms 6476 KB correct
65 Correct 279 ms 6440 KB correct
66 Correct 949 ms 6636 KB correct
67 Correct 939 ms 6972 KB correct
68 Correct 928 ms 6480 KB correct
69 Correct 938 ms 7188 KB correct
70 Correct 2 ms 376 KB correct
71 Correct 533 ms 6628 KB correct
72 Correct 932 ms 7404 KB correct
73 Correct 2 ms 376 KB correct
74 Correct 943 ms 6660 KB correct
75 Correct 918 ms 6396 KB correct
76 Correct 308 ms 2764 KB correct
77 Correct 942 ms 6724 KB correct
78 Correct 952 ms 6640 KB correct
79 Correct 938 ms 6600 KB correct
80 Correct 926 ms 6464 KB correct
81 Correct 50 ms 5588 KB correct
82 Correct 909 ms 7480 KB correct
83 Correct 514 ms 3772 KB correct
84 Correct 552 ms 4312 KB correct
85 Correct 501 ms 3940 KB correct
86 Correct 350 ms 2696 KB correct
87 Correct 245 ms 2260 KB correct
88 Correct 208 ms 1720 KB correct
89 Correct 192 ms 1660 KB correct
90 Correct 164 ms 1600 KB correct
91 Correct 51 ms 504 KB correct
92 Correct 29 ms 380 KB correct
93 Correct 495 ms 3948 KB correct
94 Correct 359 ms 3000 KB correct
95 Correct 334 ms 2716 KB correct
96 Correct 180 ms 1572 KB correct
97 Correct 211 ms 1760 KB correct
98 Correct 246 ms 2264 KB correct
99 Correct 218 ms 1856 KB correct
100 Correct 77 ms 760 KB correct
101 Correct 28 ms 504 KB correct
102 Correct 491 ms 3740 KB correct
103 Correct 490 ms 3620 KB correct
104 Correct 485 ms 3564 KB correct
105 Correct 495 ms 3872 KB correct