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Submission #293651

# Submission time Handle Problem Language Result Execution time Memory
293651 2020-09-08T09:06:42 Z shayan_p Simurgh (IOI17_simurgh) C++17
100 / 100
 794 ms 8184 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 ask(){
    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);
    }
    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];
    }

    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);
    }
    
    vector<int> ret;
    for(int i = 0; i < m; i++){
	if(know[i])
	    ret.PB(i);
    }
    return ret;
}

Compilation message

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:281:9: warning: unused variable 'ROUND' [-Wunused-variable]
  281 |     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 2688 KB correct
16 Correct 5 ms 2688 KB correct
17 Correct 5 ms 2688 KB correct
18 Correct 4 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 4 ms 2688 KB correct
23 Correct 3 ms 2720 KB correct
24 Correct 3 ms 2688 KB correct
25 Correct 2 ms 2688 KB correct
26 Correct 3 ms 2688 KB correct
27 Correct 3 ms 2688 KB correct
28 Correct 3 ms 2688 KB correct
29 Correct 2 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 3 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 2688 KB correct
16 Correct 5 ms 2688 KB correct
17 Correct 5 ms 2688 KB correct
18 Correct 4 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 4 ms 2688 KB correct
23 Correct 3 ms 2720 KB correct
24 Correct 3 ms 2688 KB correct
25 Correct 2 ms 2688 KB correct
26 Correct 3 ms 2688 KB correct
27 Correct 3 ms 2688 KB correct
28 Correct 3 ms 2688 KB correct
29 Correct 2 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 3 ms 2688 KB correct
34 Correct 122 ms 4216 KB correct
35 Correct 124 ms 4088 KB correct
36 Correct 97 ms 3712 KB correct
37 Correct 25 ms 2816 KB correct
38 Correct 125 ms 4000 KB correct
39 Correct 108 ms 3840 KB correct
40 Correct 93 ms 3712 KB correct
41 Correct 101 ms 3960 KB correct
42 Correct 100 ms 3968 KB correct
43 Correct 35 ms 3456 KB correct
44 Correct 30 ms 3200 KB correct
45 Correct 32 ms 3328 KB correct
46 Correct 27 ms 3200 KB correct
47 Correct 17 ms 2944 KB correct
48 Correct 8 ms 2688 KB correct
49 Correct 14 ms 2816 KB correct
50 Correct 17 ms 2944 KB correct
51 Correct 34 ms 3328 KB correct
52 Correct 28 ms 3200 KB correct
53 Correct 28 ms 3232 KB correct
54 Correct 35 ms 3456 KB correct
55 Correct 35 ms 3448 KB correct
56 Correct 37 ms 3328 KB correct
57 Correct 35 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 449 ms 6776 KB correct
4 Correct 786 ms 8088 KB correct
5 Correct 777 ms 8056 KB correct
6 Correct 659 ms 7928 KB correct
7 Correct 659 ms 7928 KB correct
8 Correct 656 ms 7928 KB correct
9 Correct 792 ms 8176 KB correct
10 Correct 792 ms 8052 KB correct
11 Correct 774 ms 8056 KB correct
12 Correct 785 ms 8184 KB correct
13 Correct 2 ms 2688 KB correct
14 Correct 783 ms 7928 KB correct
15 Correct 777 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 2688 KB correct
16 Correct 5 ms 2688 KB correct
17 Correct 5 ms 2688 KB correct
18 Correct 4 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 4 ms 2688 KB correct
23 Correct 3 ms 2720 KB correct
24 Correct 3 ms 2688 KB correct
25 Correct 2 ms 2688 KB correct
26 Correct 3 ms 2688 KB correct
27 Correct 3 ms 2688 KB correct
28 Correct 3 ms 2688 KB correct
29 Correct 2 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 3 ms 2688 KB correct
34 Correct 122 ms 4216 KB correct
35 Correct 124 ms 4088 KB correct
36 Correct 97 ms 3712 KB correct
37 Correct 25 ms 2816 KB correct
38 Correct 125 ms 4000 KB correct
39 Correct 108 ms 3840 KB correct
40 Correct 93 ms 3712 KB correct
41 Correct 101 ms 3960 KB correct
42 Correct 100 ms 3968 KB correct
43 Correct 35 ms 3456 KB correct
44 Correct 30 ms 3200 KB correct
45 Correct 32 ms 3328 KB correct
46 Correct 27 ms 3200 KB correct
47 Correct 17 ms 2944 KB correct
48 Correct 8 ms 2688 KB correct
49 Correct 14 ms 2816 KB correct
50 Correct 17 ms 2944 KB correct
51 Correct 34 ms 3328 KB correct
52 Correct 28 ms 3200 KB correct
53 Correct 28 ms 3232 KB correct
54 Correct 35 ms 3456 KB correct
55 Correct 35 ms 3448 KB correct
56 Correct 37 ms 3328 KB correct
57 Correct 35 ms 3328 KB correct
58 Correct 2 ms 2688 KB correct
59 Correct 2 ms 2688 KB correct
60 Correct 449 ms 6776 KB correct
61 Correct 786 ms 8088 KB correct
62 Correct 777 ms 8056 KB correct
63 Correct 659 ms 7928 KB correct
64 Correct 659 ms 7928 KB correct
65 Correct 656 ms 7928 KB correct
66 Correct 792 ms 8176 KB correct
67 Correct 792 ms 8052 KB correct
68 Correct 774 ms 8056 KB correct
69 Correct 785 ms 8184 KB correct
70 Correct 2 ms 2688 KB correct
71 Correct 783 ms 7928 KB correct
72 Correct 777 ms 8056 KB correct
73 Correct 2 ms 2688 KB correct
74 Correct 794 ms 8056 KB correct
75 Correct 752 ms 8056 KB correct
76 Correct 318 ms 4864 KB correct
77 Correct 774 ms 8184 KB correct
78 Correct 782 ms 8060 KB correct
79 Correct 769 ms 8056 KB correct
80 Correct 763 ms 8056 KB correct
81 Correct 537 ms 7544 KB correct
82 Correct 760 ms 7928 KB correct
83 Correct 482 ms 5632 KB correct
84 Correct 231 ms 6272 KB correct
85 Correct 201 ms 6264 KB correct
86 Correct 137 ms 4856 KB correct
87 Correct 103 ms 4480 KB correct
88 Correct 86 ms 3840 KB correct
89 Correct 87 ms 3840 KB correct
90 Correct 79 ms 3832 KB correct
91 Correct 47 ms 2816 KB correct
92 Correct 28 ms 2816 KB correct
93 Correct 203 ms 6264 KB correct
94 Correct 136 ms 4736 KB correct
95 Correct 129 ms 4864 KB correct
96 Correct 82 ms 3832 KB correct
97 Correct 84 ms 3840 KB correct
98 Correct 98 ms 4508 KB correct
99 Correct 86 ms 3840 KB correct
100 Correct 53 ms 3072 KB correct
101 Correct 31 ms 2940 KB correct
102 Correct 225 ms 5496 KB correct
103 Correct 224 ms 5372 KB correct
104 Correct 221 ms 5496 KB correct
105 Correct 227 ms 5368 KB correct