oj.uz

Submission #592939

# Submission time Handle Problem Language Result Execution time Memory
592939 2022-07-09T21:01:10 Z Bobaa Min-max tree (BOI18_minmaxtree) C++17
100 / 100
 148 ms 22788 KB 
#include <bits/stdc++.h>
using namespace std; 

const int inf = 1e9 + 7; 
const int maxn = 7e4 + 5; 

int n; 

struct query {
	int x, y, z; 
	char scan() {
		static char in[10]; 
		scanf("%s %d %d %d", in, &x, &y, &z); 
		return *in; 
	}
};

vector<int> edge[maxn]; 
vector<query> qs[256]; 
int par[maxn][17]; 
int nxt[maxn]; 
int dep[maxn]; 

void dfs(int x, int p) {
	par[x][0] = p; 
	dep[x] = dep[p] + 1; 
	for (int i = 1; i < 17; i++) par[x][i] = par[par[x][i - 1]][i - 1]; 
	for (int i : edge[x]) {
		if (i == p) continue; 
		dfs(i, x); 
	}
}

int lca(int x, int y) {
	if (dep[x] < dep[y]) swap(x, y);
	for (int i = 17; i--; ) if ((dep[x] - dep[y]) >> i) x = par[x][i]; 
	if (x == y) return x; 
	for (int i = 17; i--; ) if (par[x][i] != par[y][i]) {
		x = par[x][i]; 
		y = par[y][i]; 
	}
	return par[x][0]; 
}

int mn[maxn]; 
int mx[maxn]; 

int paint(int c[], int s, int e, int x) {
	if (dep[s] <= dep[e]) return s; 
	if (c[s]) return nxt[s] = paint(c, nxt[s], e, x); 
	c[s] = x; 
	return nxt[s] = paint(c, par[s][0], e, x); 
}

int find(vector<int> &v, int x) {
	return lower_bound(v.begin(), v.end(), x) - v.begin(); 
}

struct matching {
	vector<int> edge[maxn]; 
	int rev[maxn]; 
	int vis[maxn]; 
	int lv[maxn]; 
	int n; 
	
	void bfs() {
		queue<int> q; 
		for (int i = 2; i <= n; i++) {
			if (vis[i]) lv[i] = inf; 
			else {
				lv[i] = 0; 
				q.push(i); 
			}
		}
		while (!q.empty()) {
			int x = q.front(); 
			q.pop(); 
			for (int i : edge[x]) if (rev[i]) {
				if (lv[rev[i]] < inf) continue; 
				lv[rev[i]] = lv[x] + 1; 
				q.push(rev[i]); 
			}
		}
	}
	
	int dfs(int x) {
		for (int i : edge[x]) if (rev[i] == 0 || lv[rev[i]] == lv[x] + 1 && dfs(rev[i])) {
			vis[x] = 1; 
			rev[i] = x; 
			return 1; 
		}
		return 0; 
	}
	
	int process(int N) {
		n = N; 
		int ret = 0; 
		while (1) {
			bfs(); 
			int res = 0; 
			for (int i = 2; i <= n; i++) {
				if (vis[i]) continue; 
				res += dfs(i); 
			}
			if (res == 0) break; 
			ret += res; 
		}
		return ret; 
	}
} mt; 

int main() {
	scanf("%d", &n); 
	for (int i = 1, a, b; i < n; i++) {
		scanf("%d %d", &a, &b); 
		edge[a].push_back(b); 
		edge[b].push_back(a); 
	}
	dfs(1, 0); 
	int k; 
	scanf("%d", &k); 
	vector<int> cp; 
	for (int i = 0; i < k; i++) {
		query q; 
		char c = q.scan(); 
		qs[c].push_back(q); 
		cp.push_back(q.z); 
	}
	cp.push_back(0); 
	sort(cp.begin(), cp.end()); 
	cp.erase(unique(cp.begin(), cp.end()), cp.end()); 
	sort(qs['m'].begin(), qs['m'].end(), [&](const query &x, const query &y) {
		return x.z > y.z; 
	}); 
	sort(qs['M'].begin(), qs['M'].end(), [&](const query &x, const query &y) {
		return x.z < y.z; 
	}); 
	for (query i : qs['m']) {
		int p = lca(i.x, i.y); 
		paint(mn, i.x, p, i.z); 
		paint(mn, i.y, p, i.z); 
	}
	for (query i : qs['M']) {
		int p = lca(i.x, i.y); 
		paint(mx, i.x, p, i.z); 
		paint(mx, i.y, p, i.z);
	}
	for (int i = 2; i <= n; i++) {
		if (mn[i]) mt.edge[i].push_back(find(cp, mn[i])); 
		if (mn[i] == mx[i]) continue; 
		if (mx[i]) mt.edge[i].push_back(find(cp, mx[i])); 
	}
	mt.process(n); 
	for (int i = 1; i < cp.size(); i++) mn[mt.rev[i]] = cp[i]; 
	for (int i = 2; i <= n; i++) printf("%d %d %d\n", i, par[i][0], mn[i]); 
	return 0; 
}

Compilation message

minmaxtree.cpp: In member function 'int matching::dfs(int)':
minmaxtree.cpp:87:68: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   87 |   for (int i : edge[x]) if (rev[i] == 0 || lv[rev[i]] == lv[x] + 1 && dfs(rev[i])) {
      |                                            ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
minmaxtree.cpp: In function 'int main()':
minmaxtree.cpp:126:6: warning: array subscript has type 'char' [-Wchar-subscripts]
  126 |   qs[c].push_back(q);
      |      ^
minmaxtree.cpp:154:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  154 |  for (int i = 1; i < cp.size(); i++) mn[mt.rev[i]] = cp[i];
      |                  ~~^~~~~~~~~~~
minmaxtree.cpp:113:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  113 |  scanf("%d", &n);
      |  ~~~~~^~~~~~~~~~
minmaxtree.cpp:115:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  115 |   scanf("%d %d", &a, &b);
      |   ~~~~~^~~~~~~~~~~~~~~~~
minmaxtree.cpp:121:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  121 |  scanf("%d", &k);
      |  ~~~~~^~~~~~~~~~
minmaxtree.cpp: In member function 'char query::scan()':
minmaxtree.cpp:13:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |   scanf("%s %d %d %d", in, &x, &y, &z);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3540 KB Output is correct
2 Correct 2 ms 3540 KB Output is correct
3 Correct 2 ms 3540 KB Output is correct
4 Correct 2 ms 3604 KB Output is correct

Subtask #2
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 131 ms 21588 KB Output is correct
2 Correct 101 ms 19580 KB Output is correct
3 Correct 111 ms 20464 KB Output is correct
4 Correct 113 ms 22104 KB Output is correct
5 Correct 127 ms 20088 KB Output is correct
6 Correct 108 ms 20092 KB Output is correct
7 Correct 98 ms 19584 KB Output is correct

Subtask #3
29.0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 81 ms 16828 KB Output is correct
2 Correct 76 ms 16976 KB Output is correct
3 Correct 85 ms 18220 KB Output is correct
4 Correct 78 ms 19180 KB Output is correct
5 Correct 99 ms 17460 KB Output is correct
6 Correct 91 ms 17976 KB Output is correct
7 Correct 83 ms 17328 KB Output is correct
8 Correct 81 ms 17248 KB Output is correct

Subtask #4
42.0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3540 KB Output is correct
2 Correct 2 ms 3540 KB Output is correct
3 Correct 2 ms 3540 KB Output is correct
4 Correct 2 ms 3604 KB Output is correct
5 Correct 131 ms 21588 KB Output is correct
6 Correct 101 ms 19580 KB Output is correct
7 Correct 111 ms 20464 KB Output is correct
8 Correct 113 ms 22104 KB Output is correct
9 Correct 127 ms 20088 KB Output is correct
10 Correct 108 ms 20092 KB Output is correct
11 Correct 98 ms 19584 KB Output is correct
12 Correct 81 ms 16828 KB Output is correct
13 Correct 76 ms 16976 KB Output is correct
14 Correct 85 ms 18220 KB Output is correct
15 Correct 78 ms 19180 KB Output is correct
16 Correct 99 ms 17460 KB Output is correct
17 Correct 91 ms 17976 KB Output is correct
18 Correct 83 ms 17328 KB Output is correct
19 Correct 81 ms 17248 KB Output is correct
20 Correct 114 ms 19740 KB Output is correct
21 Correct 103 ms 18712 KB Output is correct
22 Correct 103 ms 18824 KB Output is correct
23 Correct 101 ms 18952 KB Output is correct
24 Correct 125 ms 21688 KB Output is correct
25 Correct 148 ms 22788 KB Output is correct
26 Correct 126 ms 22376 KB Output is correct
27 Correct 132 ms 21432 KB Output is correct
28 Correct 116 ms 20056 KB Output is correct
29 Correct 120 ms 20108 KB Output is correct
30 Correct 115 ms 19268 KB Output is correct
31 Correct 111 ms 19368 KB Output is correct
32 Correct 114 ms 19792 KB Output is correct
33 Correct 110 ms 19356 KB Output is correct
34 Correct 110 ms 19376 KB Output is correct
35 Correct 112 ms 19180 KB Output is correct