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Submission #293648

# Submission time Handle Problem Language Result Execution time Memory
293648 2020-09-08T09:03:36 Z shayan_p Simurgh (IOI17_simurgh) C++17
100 / 100
 804 ms 9056 KB 
// Oh damn! Suddenly you're free to fly...

#include<bits/stdc++.h>
#include "simurgh.h"

#define F first
#define S second
#define PB push_back
#define sz(s) int((s).size())
#define bit(n,k) (((n)>>(k))&1)

using namespace std;

typedef long long ll;
typedef pair<int,int> pii;

const int maxn = 510, maxM = 3e5 + 10, mod = 1e9 + 7, inf = 1e9 + 10;

vector<pii> v[maxn];

set<int> TREE;
int h[maxn];
pii up[maxn];
bool mark[maxn];

int know[maxM];

int parid[maxn], par[maxn];

int ASKED = 0;

int ask(){
    //    assert(++ASKED <= 10000);//////////////    
    vector<int> tmp;
    for(int x : TREE)
	tmp.PB(x);
    return count_common_roads(tmp);
}

template<int N> struct DSU{
    int pr[N];
    DSU(){
	memset(pr, -1, sizeof pr);
    }
    void clear(){
	memset(pr, -1, sizeof pr);
    }
    int fnd(int u){
	return pr[u] < 0 ? u : pr[u] = fnd(pr[u]);
    }
    bool mrg(int a, int b){
	if( (a = fnd(a)) == (b = fnd(b)) )
	    return 0;
	if(pr[a] > pr[b])
	    swap(a, b);
	pr[a]+= pr[b];
	pr[b] = a;
	return 1;
    }
    void mrg_know(int a, int b){
	a = fnd(a), b = fnd(b);	
	if(know[b] != -1)
	    know[a] = know[b];
	else
	    know[b] = know[a];
    }
    void put_know(int a, int x){
	a = fnd(a);
	know[a] = x;
    }
};DSU<maxM> dsu;

void prep(int u, int pr = -1){
    par[u] = pr;
    mark[u] = 1;
    h[u] = (pr == -1 ? 0 : (h[pr] + 1));
    up[u] = {h[u], -1};
    for(auto [y, c] : v[u]){
	if(!mark[y]){
	    parid[y] = c;
	    prep(y, u);
	    TREE.insert(c);
	    up[u] = min(up[u], up[y]);
	}
	else if(y != pr){
	    up[u] = min(up[u], (pii){h[y], c});
	}
    }    
}

int tree_ask;
vector<int> A, B;
int n, m;

void check(int in, int out){
    TREE.insert(out);
    TREE.erase(in);
    int x = ask();
    if(x == tree_ask){
	dsu.mrg_know(in, out);
	dsu.mrg(in, out);	    
    }
    if(x < tree_ask){
	dsu.put_know(in, 1);
	dsu.put_know(out, 0);
    }
    if(x > tree_ask){
	dsu.put_know(in, 0);
	dsu.put_know(out, 1);
    }
    TREE.insert(in);
    TREE.erase(out);
}

bool mark_calc[maxn];

void dfs(int u){
    if(par[u] != -1 && up[u].F == h[u]){
	dsu.put_know(parid[u], 1);
    }
    mark[u] = 1;

    pair<int, pii> mnh = {h[u], {-1, -1}};
    for(auto [y, c] : v[u]){
	mnh = min(mnh, (pair<int, pii>){h[y], {y, c}});
    }
    if(mnh.F < h[u] - 1){	
	int tmp = u;
	while(tmp != mnh.S.F && !mark_calc[tmp]){
	    mark_calc[tmp] = 1;
	    check(parid[tmp], mnh.S.S);
	    tmp = par[tmp];
	}
	if(tmp != mnh.S.F){
	    check(parid[tmp], mnh.S.S);
	}
	if(know[ dsu.fnd(parid[u]) ] == -1){
	    dsu.put_know(parid[u], 0);
	}
    }
    for(auto [y, c] : v[u]){
	if(!mark[y])
	    dfs(y);
    }
}




bool bad_edge[maxM];

vector<int> wave;

void dfs2(int u){
    mark[u] = 1;
    for(auto [y, c] : v[u]){
	if(bad_edge[c] || mark[y])
	    continue;
	wave.PB(c);
	bad_edge[c] = 1;
	dfs2(y);
    }
}

DSU<maxn> dsu2;

vector<int> dfs_tree;

int jungle(vector<int> vec){
    dsu2.clear();
    TREE.clear();
    for(int id : vec){
	dsu2.mrg(A[id], B[id]);
	TREE.insert(id);
    }
    int lz = 0;
    for(int i : dfs_tree){
	if(dsu2.mrg(A[i], B[i]))
	    lz+= know[i], TREE.insert(i);
    }
    //    assert(sz(TREE) == n-1);
    return ask() - lz;
}

void solve(vector<int> ed, int cnt = -1){
    if(ed.empty())
	return;
    if(cnt == -1)
	cnt = jungle(ed);
    if(cnt == 0){
	for(int id : ed)
	    know[id] = 0;
	return;
    }
    if(cnt == sz(ed)){
	for(int id : ed)
	    know[id] = 1;
	return;
    }
    int mid = sz(ed) / 2;
    vector<int> v1, v2;
    for(int i = 0; i < sz(ed); i++){
	if(i < mid)
	    v1.PB(ed[i]);
	else
	    v2.PB(ed[i]);
    }
    int c = jungle(v1);
    solve(v1, c);
    solve(v2, cnt - c);
}

void ASSERT(bool x, int sig){
    if(!x)
	exit(sig);
}

vector<int> find_roads(int n, vector<int> A, vector<int> B){
    ::A = A, ::B = B, ::n = n;
    m = sz(A);

    memset(know, -1, sizeof know);
    
    for(int i = 0; i < m; i++){
	v[A[i]].PB({B[i], i});
	v[B[i]].PB({A[i], i});
    }

    prep(0);
    tree_ask = ask();
    for(int id = 0; id < m; id++){
	if(abs(h[A[id]] - h[B[id]]) > 1){
	    if(h[A[id]] < h[B[id]])
		swap(A[id], B[id]);
	    int tmp = A[id];
	    
	    int ONE = -1;
	    while(tmp != B[id]){
		if(know[ dsu.fnd(parid[tmp]) ] == -1){
		    check(parid[tmp], id);
		}
		else{
		    ONE = parid[tmp];
		}
		tmp = par[tmp];
	    }

	    bool is = 0;
	    tmp = A[id];
	    while(tmp != B[id]){
		if(know[ dsu.fnd(parid[tmp]) ] == -1){
		    is = 1;
		}
		tmp = par[tmp];
	    }

	    if(is){
		if(ONE != -1)
		    check(ONE, id);
		tmp = A[id];
		if(know[ dsu.fnd(id) ] == -1)
		    dsu.put_know(id, 0);
	    }
	}	    
    }
    for(int i : TREE){
	if(know[ dsu.fnd(i) ] == -1)// boreshi
	    dsu.put_know(i, 1);
    }
    
    for(int i : TREE)
	dfs_tree.PB(i);
    
    int TOT = 0;

    for(int id : TREE){
	know[id] = know[ dsu.fnd(id) ];
	assert(know[id] != -1);

	bad_edge[id] = 1;

	TOT+= know[id];
    }
    
    // assert(TOT == ask());
    //    ASSERT(TOT == tree_ask, 1);
    
    int ROUND = 0;
    while(true){
	memset(mark, 0, sizeof mark);
	wave.clear();
	for(int i = 0; i < n; i++){
	    if(!mark[i])
		dfs2(i);
	}
	if(wave.empty())
	    break;
	solve(wave);
	//	ASSERT(sz(wave) < n, 2);
	//	ASSERT(++ROUND <= n, 3);
    }
    
    vector<int> ret;
    for(int i = 0; i < m; i++){
	//	ASSERT(know[i] != -1, 4);
	if(know[i])
	    ret.PB(i);
    }
    //    ASSERT(sz(ret) == n-1, 5);
    return ret;
}

Compilation message

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:288:9: warning: unused variable 'ROUND' [-Wunused-variable]
  288 |     int ROUND = 0;
      |         ^~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2688 KB correct
2 Correct 2 ms 2688 KB correct
3 Correct 2 ms 2688 KB correct
4 Correct 2 ms 2688 KB correct
5 Correct 2 ms 2688 KB correct
6 Correct 2 ms 2688 KB correct
7 Correct 2 ms 2688 KB correct
8 Correct 2 ms 2688 KB correct
9 Correct 2 ms 2688 KB correct
10 Correct 2 ms 2688 KB correct
11 Correct 2 ms 2688 KB correct
12 Correct 2 ms 2688 KB correct
13 Correct 2 ms 2688 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2688 KB correct
2 Correct 2 ms 2688 KB correct
3 Correct 2 ms 2688 KB correct
4 Correct 2 ms 2688 KB correct
5 Correct 2 ms 2688 KB correct
6 Correct 2 ms 2688 KB correct
7 Correct 2 ms 2688 KB correct
8 Correct 2 ms 2688 KB correct
9 Correct 2 ms 2688 KB correct
10 Correct 2 ms 2688 KB correct
11 Correct 2 ms 2688 KB correct
12 Correct 2 ms 2688 KB correct
13 Correct 2 ms 2688 KB correct
14 Correct 5 ms 2688 KB correct
15 Correct 4 ms 2720 KB correct
16 Correct 4 ms 2688 KB correct
17 Correct 5 ms 2688 KB correct
18 Correct 5 ms 2688 KB correct
19 Correct 5 ms 2688 KB correct
20 Correct 4 ms 2688 KB correct
21 Correct 4 ms 2688 KB correct
22 Correct 3 ms 2688 KB correct
23 Correct 3 ms 2688 KB correct
24 Correct 3 ms 2688 KB correct
25 Correct 3 ms 2688 KB correct
26 Correct 3 ms 2688 KB correct
27 Correct 3 ms 2688 KB correct
28 Correct 2 ms 2688 KB correct
29 Correct 3 ms 2688 KB correct
30 Correct 3 ms 2688 KB correct
31 Correct 3 ms 2688 KB correct
32 Correct 3 ms 2688 KB correct
33 Correct 4 ms 2688 KB correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2688 KB correct
2 Correct 2 ms 2688 KB correct
3 Correct 2 ms 2688 KB correct
4 Correct 2 ms 2688 KB correct
5 Correct 2 ms 2688 KB correct
6 Correct 2 ms 2688 KB correct
7 Correct 2 ms 2688 KB correct
8 Correct 2 ms 2688 KB correct
9 Correct 2 ms 2688 KB correct
10 Correct 2 ms 2688 KB correct
11 Correct 2 ms 2688 KB correct
12 Correct 2 ms 2688 KB correct
13 Correct 2 ms 2688 KB correct
14 Correct 5 ms 2688 KB correct
15 Correct 4 ms 2720 KB correct
16 Correct 4 ms 2688 KB correct
17 Correct 5 ms 2688 KB correct
18 Correct 5 ms 2688 KB correct
19 Correct 5 ms 2688 KB correct
20 Correct 4 ms 2688 KB correct
21 Correct 4 ms 2688 KB correct
22 Correct 3 ms 2688 KB correct
23 Correct 3 ms 2688 KB correct
24 Correct 3 ms 2688 KB correct
25 Correct 3 ms 2688 KB correct
26 Correct 3 ms 2688 KB correct
27 Correct 3 ms 2688 KB correct
28 Correct 2 ms 2688 KB correct
29 Correct 3 ms 2688 KB correct
30 Correct 3 ms 2688 KB correct
31 Correct 3 ms 2688 KB correct
32 Correct 3 ms 2688 KB correct
33 Correct 4 ms 2688 KB correct
34 Correct 126 ms 3996 KB correct
35 Correct 118 ms 3960 KB correct
36 Correct 96 ms 3712 KB correct
37 Correct 24 ms 2816 KB correct
38 Correct 123 ms 4088 KB correct
39 Correct 109 ms 3960 KB correct
40 Correct 93 ms 3712 KB correct
41 Correct 100 ms 3968 KB correct
42 Correct 102 ms 4088 KB correct
43 Correct 35 ms 3456 KB correct
44 Correct 30 ms 3212 KB correct
45 Correct 33 ms 3328 KB correct
46 Correct 27 ms 3256 KB correct
47 Correct 18 ms 2944 KB correct
48 Correct 8 ms 2688 KB correct
49 Correct 14 ms 2816 KB correct
50 Correct 18 ms 2944 KB correct
51 Correct 34 ms 3456 KB correct
52 Correct 28 ms 3200 KB correct
53 Correct 28 ms 3200 KB correct
54 Correct 36 ms 3456 KB correct
55 Correct 35 ms 3328 KB correct
56 Correct 36 ms 3328 KB correct
57 Correct 36 ms 3328 KB correct

Subtask #4
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2688 KB correct
2 Correct 2 ms 2688 KB correct
3 Correct 446 ms 6520 KB correct
4 Correct 777 ms 8080 KB correct
5 Correct 775 ms 7928 KB correct
6 Correct 663 ms 7928 KB correct
7 Correct 656 ms 7928 KB correct
8 Correct 654 ms 7932 KB correct
9 Correct 790 ms 8056 KB correct
10 Correct 767 ms 8056 KB correct
11 Correct 778 ms 8188 KB correct
12 Correct 773 ms 8056 KB correct
13 Correct 2 ms 2688 KB correct
14 Correct 762 ms 8052 KB correct
15 Correct 769 ms 8056 KB correct

Subtask #5
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2688 KB correct
2 Correct 2 ms 2688 KB correct
3 Correct 2 ms 2688 KB correct
4 Correct 2 ms 2688 KB correct
5 Correct 2 ms 2688 KB correct
6 Correct 2 ms 2688 KB correct
7 Correct 2 ms 2688 KB correct
8 Correct 2 ms 2688 KB correct
9 Correct 2 ms 2688 KB correct
10 Correct 2 ms 2688 KB correct
11 Correct 2 ms 2688 KB correct
12 Correct 2 ms 2688 KB correct
13 Correct 2 ms 2688 KB correct
14 Correct 5 ms 2688 KB correct
15 Correct 4 ms 2720 KB correct
16 Correct 4 ms 2688 KB correct
17 Correct 5 ms 2688 KB correct
18 Correct 5 ms 2688 KB correct
19 Correct 5 ms 2688 KB correct
20 Correct 4 ms 2688 KB correct
21 Correct 4 ms 2688 KB correct
22 Correct 3 ms 2688 KB correct
23 Correct 3 ms 2688 KB correct
24 Correct 3 ms 2688 KB correct
25 Correct 3 ms 2688 KB correct
26 Correct 3 ms 2688 KB correct
27 Correct 3 ms 2688 KB correct
28 Correct 2 ms 2688 KB correct
29 Correct 3 ms 2688 KB correct
30 Correct 3 ms 2688 KB correct
31 Correct 3 ms 2688 KB correct
32 Correct 3 ms 2688 KB correct
33 Correct 4 ms 2688 KB correct
34 Correct 126 ms 3996 KB correct
35 Correct 118 ms 3960 KB correct
36 Correct 96 ms 3712 KB correct
37 Correct 24 ms 2816 KB correct
38 Correct 123 ms 4088 KB correct
39 Correct 109 ms 3960 KB correct
40 Correct 93 ms 3712 KB correct
41 Correct 100 ms 3968 KB correct
42 Correct 102 ms 4088 KB correct
43 Correct 35 ms 3456 KB correct
44 Correct 30 ms 3212 KB correct
45 Correct 33 ms 3328 KB correct
46 Correct 27 ms 3256 KB correct
47 Correct 18 ms 2944 KB correct
48 Correct 8 ms 2688 KB correct
49 Correct 14 ms 2816 KB correct
50 Correct 18 ms 2944 KB correct
51 Correct 34 ms 3456 KB correct
52 Correct 28 ms 3200 KB correct
53 Correct 28 ms 3200 KB correct
54 Correct 36 ms 3456 KB correct
55 Correct 35 ms 3328 KB correct
56 Correct 36 ms 3328 KB correct
57 Correct 36 ms 3328 KB correct
58 Correct 2 ms 2688 KB correct
59 Correct 2 ms 2688 KB correct
60 Correct 446 ms 6520 KB correct
61 Correct 777 ms 8080 KB correct
62 Correct 775 ms 7928 KB correct
63 Correct 663 ms 7928 KB correct
64 Correct 656 ms 7928 KB correct
65 Correct 654 ms 7932 KB correct
66 Correct 790 ms 8056 KB correct
67 Correct 767 ms 8056 KB correct
68 Correct 778 ms 8188 KB correct
69 Correct 773 ms 8056 KB correct
70 Correct 2 ms 2688 KB correct
71 Correct 762 ms 8052 KB correct
72 Correct 769 ms 8056 KB correct
73 Correct 2 ms 2688 KB correct
74 Correct 782 ms 8076 KB correct
75 Correct 753 ms 8952 KB correct
76 Correct 306 ms 4992 KB correct
77 Correct 770 ms 8876 KB correct
78 Correct 776 ms 8952 KB correct
79 Correct 783 ms 8864 KB correct
80 Correct 804 ms 8844 KB correct
81 Correct 542 ms 8184 KB correct
82 Correct 769 ms 9056 KB correct
83 Correct 483 ms 6264 KB correct
84 Correct 240 ms 6812 KB correct
85 Correct 198 ms 6648 KB correct
86 Correct 140 ms 5268 KB correct
87 Correct 101 ms 4736 KB correct
88 Correct 87 ms 4096 KB correct
89 Correct 84 ms 3968 KB correct
90 Correct 74 ms 3960 KB correct
91 Correct 46 ms 2944 KB correct
92 Correct 28 ms 2816 KB correct
93 Correct 197 ms 6648 KB correct
94 Correct 132 ms 5120 KB correct
95 Correct 128 ms 5240 KB correct
96 Correct 80 ms 3968 KB correct
97 Correct 87 ms 4096 KB correct
98 Correct 103 ms 4736 KB correct
99 Correct 86 ms 4096 KB correct
100 Correct 56 ms 3072 KB correct
101 Correct 29 ms 2816 KB correct
102 Correct 225 ms 5864 KB correct
103 Correct 223 ms 5880 KB correct
104 Correct 222 ms 5884 KB correct
105 Correct 225 ms 5760 KB correct