oj.uz

Submission #1018977

# Submission time Handle Problem Language Result Execution time Memory
1018977 2024-07-10T11:28:10 Z lovrot Simurgh (IOI17_simurgh) C++17
100 / 100
 660 ms 8428 KB 
#include "simurgh.h"
#include <cstring>
#include <cstdio>
#include <vector>
#include <set>
#include <algorithm>
#include <cassert>

#define X first
#define Y second
#define PB push_back

using namespace std;

typedef pair<int, int> pii;

const int N = 510;
const int M = N * N;

int n, m, uu[M], vv[M];
vector<pii> g[N];

bool isb[M];
vector<pii> mst;

int dep[N], mind[N]; // memset(dep)

int dfstree(int u, int p, int pi) { 
	mind[u] = dep[u];
	for(pii e : g[u]) { 
		int v = e.X, i = e.Y;

		if(v != p) { 
			if(dep[v] == -1) { 
				dep[v] = dep[u] + 1;
				mind[u] = min(mind[u], dfstree(v, u, i));
			} else if( dep[v] < dep[u]) { 
				mind[u] = min(mind[u], dep[v]);
			}
		}
	}
	
	if(pi != -1 && mind[u] >= dep[u]) { 
		mst.PB({pi, 1});
		isb[pi] = 1;
	}

	return mind[u];
}

void bridge() { 
	memset(dep, -1, sizeof(dep));
	dep[0] = 0;
	dfstree(0, -1, -1);
}

int un[N], siz[N];

void clear() { 
	memset(un, -1, sizeof(un));
	for(int i = 0; i < n; ++i) { 
		siz[i] = 1;
	}
}

int trazi(int u) { return un[u] == -1 ? u : un[u] = trazi(un[u]); }
bool unija(int u, int v) { 
	u = trazi(u);
	v = trazi(v);
	if(u == v) { return 0; }

	if(siz[u] < siz[v]) { swap(u, v); }
	un[v] = u;
	siz[u] += siz[v];
	return 1;
}

vector<int> qry;

int fillup(vector<int> &e, bool f) { 
	clear();
	qry.clear();
	int ret = 0;

	for(int i : e) { 
		unija(uu[i], vv[i]);
		qry.PB(i);
	}

	if(f == 0) { 
		for(int i = 0; i < m; ++i) { 
			if(unija(uu[i], vv[i])) { 
				qry.PB(i);
			}
		}
	} else { 
		for(pii i : mst) { 
			if(unija(uu[i.X], vv[i.X])) { 
				qry.PB(i.X);
				ret += i.Y;
			}
		}
	}
	return ret;
}

int bio[N], bioe[M], val[M];
vector<int> tmp, cp, pth;

void comp(int u) { 
	if(bio[u] != -1) { return; }
	bio[u] = 0;
	cp.PB(u);

	for(pii e : g[u]) { 
		if(!isb[e.Y]) { 
			comp(e.X);
		}
	}
}

bool tried[N];
int spec[2], sp;

bool dfs(int u) {
	bio[u] = 1;
	tried[u] = 1;
	for(pii e : g[u]) { 
		int v = e.X, i = e.Y;
		if(!isb[i] && !bioe[i] && bio[v] != 1 && !tried[v]) { 
			tmp.PB(i);
			bioe[i] = 1;
			if(bio[v] == 2) { 
				spec[sp] = v;
				return 1;
			} else {
				if(dfs(v)) { 
					return 1; 
				}
				bioe[i] = 0;
				tmp.pop_back();
			}
		}
	}
	bio[u] = 0;
	return 0;
}

bool path(int u, int t, int pr = -1) { 
	if(u == t) { return 1; }
	bool ret = 0;
	for(pii p : g[u]) { 
		int v = p.X, ind = p.Y;
		if(v != pr && !isb[ind] && bioe[ind] == 1 && bio[v] == 2) { 
			if(path(v, t, u)) { 
				pth.PB(ind);
				return 1;
			}
		}
	}
	return 0;
}

void cycle(vector<int> &e) {
	pth.clear();
	path(spec[0], spec[1]);
	int f = -1;
	for(int i = 0; i < pth.size(); ++i) {
		if(val[pth[i]] == 0) { 
			f = i;
		}
	}

	int xam = -1;
	if(f != -1) { 
		vector<int> fu;
		for(int i = 0; i < pth.size(); ++i) { 
			if(i != f) {
				fu.PB(pth[i]);
			}
		}
		for(int i : e) { 
			fu.PB(i);
		}
		fillup(fu, 0);

		xam = count_common_roads(qry);
	}

	vector<pii> res;
	for(int i = 0; i < e.size(); ++i) { 
		vector<int> fu;
		for(int j : pth) {
			fu.PB(j);
		}
		for(int j = 0; j < e.size(); ++j) { 
			if(j != i) {
				fu.PB(e[j]);
			}
		}
		
		fillup(fu, 0);
		res.PB({e[i], count_common_roads(qry)});
		xam = max(xam, res.back().Y);
	}

	for(int i = 0; i < (int) res.size() - 1; ++i) { 
		mst.PB({res[i].X, xam - res[i].Y});
		val[res[i].X] = xam - res[i].Y;
	}
	bioe[res.back().X] = 0;
}

void ear() {
	memset(bio, -1, sizeof(bio));

	for(int i = 0; i < n; ++i) { 
		if(bio[i] == -1) { 
			cp.clear();
			comp(i);
			bio[i] = 2;

			for(int j : cp) { 
				if(bio[j] != 2) {
					tmp.clear();
					memset(tried, 0, sizeof(tried));
					sp = 0; dfs(j); 
					memset(tried, 0, sizeof(tried));
					sp = 1; dfs(j);
					
					cycle(tmp);

					for(int k : tmp) { 
						bio[uu[k]] = 2;
						bio[vv[k]] = 2;
					}
				}
			}
		}
	}
}

bool ans[M];
int deg[N], cnt = 0;

int query(vector<int> &q) {
	int d = fillup(q, 1);
	return count_common_roads(qry) - d;
}

int leaf(int u) { 
	vector<int> ng;	
	for(pii e : g[u]) { 
		if(!ans[e.Y]) { 
			ng.PB(e.Y); 
		}
	}

	for(; ng.size() > 1; ) {
		vector<int> q;
		
		int k = (ng.size() + 1) / 2;
		for(int i = 0; i < k; ++i) { 
			q.PB(ng[i]);
		}

		if(query(q)) { 
			ng.erase(ng.begin() + k, ng.end());
		} else {
			ng.erase(ng.begin(), ng.begin() + k);
		}
	}

	return ng[0];
}

vector<int> find_roads(int nn, vector<int> A, vector<int> B) {
	n = nn;
	m = A.size();
	for(int i = 0; i < m; ++i) { 
		uu[i] = A[i];
		vv[i] = B[i];
		g[uu[i]].PB({vv[i], i});	
		g[vv[i]].PB({uu[i], i});	
	}

	bridge();
	ear();

	for(int i = 0; i < n; ++i) { 
		vector<int> q;
		for(pii i : g[i]) { 
			q.PB(i.Y);
		}
	
		deg[i] = query(q);
	}

	for(; cnt < n - 1; ) { 
		for(int i = 0; i < n; ++i) { 
			if(deg[i] == 1) { 
				++cnt;
				int ind = leaf(i);
				ans[ind] = 1;
				--deg[uu[ind]];
				--deg[vv[ind]];
			}
		}
	}
	
	vector<int> ret;
	for(int i = 0; i < m; ++i) { 
		if(ans[i]) { 
			ret.PB(i);
		}
	}
	return ret;
}

Compilation message

simurgh.cpp: In function 'bool path(int, int, int)':
simurgh.cpp:151:7: warning: unused variable 'ret' [-Wunused-variable]
  151 |  bool ret = 0;
      |       ^~~
simurgh.cpp: In function 'void cycle(std::vector<int>&)':
simurgh.cpp:168:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  168 |  for(int i = 0; i < pth.size(); ++i) {
      |                 ~~^~~~~~~~~~~~
simurgh.cpp:177:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  177 |   for(int i = 0; i < pth.size(); ++i) {
      |                  ~~^~~~~~~~~~~~
simurgh.cpp:191:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  191 |  for(int i = 0; i < e.size(); ++i) {
      |                 ~~^~~~~~~~~~
simurgh.cpp:196:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  196 |   for(int j = 0; j < e.size(); ++j) {
      |                  ~~^~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2396 KB correct
2 Correct 0 ms 2396 KB correct
3 Correct 0 ms 2396 KB correct
4 Correct 0 ms 2396 KB correct
5 Correct 0 ms 2396 KB correct
6 Correct 0 ms 2396 KB correct
7 Correct 1 ms 2396 KB correct
8 Correct 1 ms 2396 KB correct
9 Correct 0 ms 2396 KB correct
10 Correct 0 ms 2396 KB correct
11 Correct 0 ms 2396 KB correct
12 Correct 0 ms 2396 KB correct
13 Correct 1 ms 2392 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2396 KB correct
2 Correct 0 ms 2396 KB correct
3 Correct 0 ms 2396 KB correct
4 Correct 0 ms 2396 KB correct
5 Correct 0 ms 2396 KB correct
6 Correct 0 ms 2396 KB correct
7 Correct 1 ms 2396 KB correct
8 Correct 1 ms 2396 KB correct
9 Correct 0 ms 2396 KB correct
10 Correct 0 ms 2396 KB correct
11 Correct 0 ms 2396 KB correct
12 Correct 0 ms 2396 KB correct
13 Correct 1 ms 2392 KB correct
14 Correct 2 ms 2396 KB correct
15 Correct 2 ms 2652 KB correct
16 Correct 2 ms 2552 KB correct
17 Correct 2 ms 2396 KB correct
18 Correct 1 ms 2396 KB correct
19 Correct 1 ms 2492 KB correct
20 Correct 2 ms 2396 KB correct
21 Correct 2 ms 2396 KB correct
22 Correct 1 ms 2396 KB correct
23 Correct 1 ms 2396 KB correct
24 Correct 2 ms 2396 KB correct
25 Correct 1 ms 2452 KB correct
26 Correct 1 ms 2396 KB correct
27 Correct 1 ms 2396 KB correct
28 Correct 1 ms 2396 KB correct
29 Correct 1 ms 2396 KB correct
30 Correct 1 ms 2396 KB correct
31 Correct 2 ms 2528 KB correct
32 Correct 2 ms 2484 KB correct
33 Correct 1 ms 2396 KB correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2396 KB correct
2 Correct 0 ms 2396 KB correct
3 Correct 0 ms 2396 KB correct
4 Correct 0 ms 2396 KB correct
5 Correct 0 ms 2396 KB correct
6 Correct 0 ms 2396 KB correct
7 Correct 1 ms 2396 KB correct
8 Correct 1 ms 2396 KB correct
9 Correct 0 ms 2396 KB correct
10 Correct 0 ms 2396 KB correct
11 Correct 0 ms 2396 KB correct
12 Correct 0 ms 2396 KB correct
13 Correct 1 ms 2392 KB correct
14 Correct 2 ms 2396 KB correct
15 Correct 2 ms 2652 KB correct
16 Correct 2 ms 2552 KB correct
17 Correct 2 ms 2396 KB correct
18 Correct 1 ms 2396 KB correct
19 Correct 1 ms 2492 KB correct
20 Correct 2 ms 2396 KB correct
21 Correct 2 ms 2396 KB correct
22 Correct 1 ms 2396 KB correct
23 Correct 1 ms 2396 KB correct
24 Correct 2 ms 2396 KB correct
25 Correct 1 ms 2452 KB correct
26 Correct 1 ms 2396 KB correct
27 Correct 1 ms 2396 KB correct
28 Correct 1 ms 2396 KB correct
29 Correct 1 ms 2396 KB correct
30 Correct 1 ms 2396 KB correct
31 Correct 2 ms 2528 KB correct
32 Correct 2 ms 2484 KB correct
33 Correct 1 ms 2396 KB correct
34 Correct 77 ms 3852 KB correct
35 Correct 62 ms 3792 KB correct
36 Correct 59 ms 3420 KB correct
37 Correct 10 ms 2392 KB correct
38 Correct 65 ms 3836 KB correct
39 Correct 81 ms 3672 KB correct
40 Correct 47 ms 3420 KB correct
41 Correct 68 ms 3832 KB correct
42 Correct 63 ms 3676 KB correct
43 Correct 46 ms 3392 KB correct
44 Correct 34 ms 2904 KB correct
45 Correct 38 ms 3160 KB correct
46 Correct 30 ms 2908 KB correct
47 Correct 18 ms 2648 KB correct
48 Correct 4 ms 2396 KB correct
49 Correct 9 ms 2600 KB correct
50 Correct 18 ms 2652 KB correct
51 Correct 44 ms 3164 KB correct
52 Correct 31 ms 3108 KB correct
53 Correct 34 ms 3056 KB correct
54 Correct 50 ms 3388 KB correct
55 Correct 35 ms 3184 KB correct
56 Correct 32 ms 3188 KB correct
57 Correct 44 ms 3200 KB correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB correct
2 Correct 0 ms 2396 KB correct
3 Correct 281 ms 6496 KB correct
4 Correct 597 ms 8192 KB correct
5 Correct 583 ms 8252 KB correct
6 Correct 518 ms 8172 KB correct
7 Correct 652 ms 8208 KB correct
8 Correct 566 ms 8192 KB correct
9 Correct 660 ms 8180 KB correct
10 Correct 629 ms 8204 KB correct
11 Correct 588 ms 8212 KB correct
12 Correct 653 ms 8168 KB correct
13 Correct 1 ms 2396 KB correct
14 Correct 432 ms 8176 KB correct
15 Correct 434 ms 8196 KB correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2396 KB correct
2 Correct 0 ms 2396 KB correct
3 Correct 0 ms 2396 KB correct
4 Correct 0 ms 2396 KB correct
5 Correct 0 ms 2396 KB correct
6 Correct 0 ms 2396 KB correct
7 Correct 1 ms 2396 KB correct
8 Correct 1 ms 2396 KB correct
9 Correct 0 ms 2396 KB correct
10 Correct 0 ms 2396 KB correct
11 Correct 0 ms 2396 KB correct
12 Correct 0 ms 2396 KB correct
13 Correct 1 ms 2392 KB correct
14 Correct 2 ms 2396 KB correct
15 Correct 2 ms 2652 KB correct
16 Correct 2 ms 2552 KB correct
17 Correct 2 ms 2396 KB correct
18 Correct 1 ms 2396 KB correct
19 Correct 1 ms 2492 KB correct
20 Correct 2 ms 2396 KB correct
21 Correct 2 ms 2396 KB correct
22 Correct 1 ms 2396 KB correct
23 Correct 1 ms 2396 KB correct
24 Correct 2 ms 2396 KB correct
25 Correct 1 ms 2452 KB correct
26 Correct 1 ms 2396 KB correct
27 Correct 1 ms 2396 KB correct
28 Correct 1 ms 2396 KB correct
29 Correct 1 ms 2396 KB correct
30 Correct 1 ms 2396 KB correct
31 Correct 2 ms 2528 KB correct
32 Correct 2 ms 2484 KB correct
33 Correct 1 ms 2396 KB correct
34 Correct 77 ms 3852 KB correct
35 Correct 62 ms 3792 KB correct
36 Correct 59 ms 3420 KB correct
37 Correct 10 ms 2392 KB correct
38 Correct 65 ms 3836 KB correct
39 Correct 81 ms 3672 KB correct
40 Correct 47 ms 3420 KB correct
41 Correct 68 ms 3832 KB correct
42 Correct 63 ms 3676 KB correct
43 Correct 46 ms 3392 KB correct
44 Correct 34 ms 2904 KB correct
45 Correct 38 ms 3160 KB correct
46 Correct 30 ms 2908 KB correct
47 Correct 18 ms 2648 KB correct
48 Correct 4 ms 2396 KB correct
49 Correct 9 ms 2600 KB correct
50 Correct 18 ms 2652 KB correct
51 Correct 44 ms 3164 KB correct
52 Correct 31 ms 3108 KB correct
53 Correct 34 ms 3056 KB correct
54 Correct 50 ms 3388 KB correct
55 Correct 35 ms 3184 KB correct
56 Correct 32 ms 3188 KB correct
57 Correct 44 ms 3200 KB correct
58 Correct 1 ms 2392 KB correct
59 Correct 0 ms 2396 KB correct
60 Correct 281 ms 6496 KB correct
61 Correct 597 ms 8192 KB correct
62 Correct 583 ms 8252 KB correct
63 Correct 518 ms 8172 KB correct
64 Correct 652 ms 8208 KB correct
65 Correct 566 ms 8192 KB correct
66 Correct 660 ms 8180 KB correct
67 Correct 629 ms 8204 KB correct
68 Correct 588 ms 8212 KB correct
69 Correct 653 ms 8168 KB correct
70 Correct 1 ms 2396 KB correct
71 Correct 432 ms 8176 KB correct
72 Correct 434 ms 8196 KB correct
73 Correct 1 ms 2396 KB correct
74 Correct 543 ms 8428 KB correct
75 Correct 544 ms 8076 KB correct
76 Correct 170 ms 4692 KB correct
77 Correct 433 ms 8196 KB correct
78 Correct 592 ms 8384 KB correct
79 Correct 487 ms 8276 KB correct
80 Correct 526 ms 8280 KB correct
81 Correct 352 ms 7776 KB correct
82 Correct 511 ms 8056 KB correct
83 Correct 276 ms 5716 KB correct
84 Correct 299 ms 6344 KB correct
85 Correct 313 ms 5976 KB correct
86 Correct 217 ms 4696 KB correct
87 Correct 182 ms 4652 KB correct
88 Correct 148 ms 3772 KB correct
89 Correct 132 ms 3724 KB correct
90 Correct 118 ms 3528 KB correct
91 Correct 37 ms 2652 KB correct
92 Correct 17 ms 2568 KB correct
93 Correct 343 ms 6132 KB correct
94 Correct 229 ms 4792 KB correct
95 Correct 225 ms 4860 KB correct
96 Correct 126 ms 3676 KB correct
97 Correct 143 ms 3788 KB correct
98 Correct 181 ms 4388 KB correct
99 Correct 136 ms 3792 KB correct
100 Correct 57 ms 2648 KB correct
101 Correct 19 ms 2396 KB correct
102 Correct 251 ms 5400 KB correct
103 Correct 244 ms 5408 KB correct
104 Correct 225 ms 5380 KB correct
105 Correct 229 ms 5208 KB correct