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Submission #309532

# Submission time Handle Problem Language Result Execution time Memory
309532 2020-10-03T18:09:28 Z bigg One-Way Streets (CEOI17_oneway) C++14
100 / 100
 315 ms 36468 KB 
#include<bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 10;
const int MAXK = 23;
int marc[MAXN], tin[MAXN], low[MAXN], comp[MAXN], T;
struct edge{
	int tipo;
	int u, v;
	void maketype(int mu, int mv, bool isont){
	//	printf("%d %d %d %d %d\n", mu, mv, isont,u, v );
		if(mu == 0){
			tipo = 3;
			return;
		}
		if(!isont){
			if(mu == u ) tipo = 1;
			else tipo = 2;
		}else{
			if(mu == comp[u]) tipo = 1;
			else tipo = 2;
		}
	}

}edges[MAXN];
vector<pair<int, int> > grafo[MAXN], grafosemponte[MAXN];
vector<int> bridge;


void makebridge( int id, int isbridge){
	if(!isbridge) edges[id].maketype(0,0,0);
	else{
		bridge.push_back(id);
	}
}

void dfsini(int x, int idp){
	marc[x] = 1;
	tin[x] = low[x] = ++T;
	for(int i = 0; i < grafo[x].size(); i++){
		int viz = grafo[x][i].first;
		int id = grafo[x][i].second;
		if(id == idp) continue;
		if(marc[viz]) low[x] = min(tin[viz], low[x]);
		else{
			dfsini(viz, id);
			makebridge(id, low[viz] > tin[x]);
			low[x] = min(low[x], low[viz]);
		}
	} 
}
int cmp;
void dfssec(int x){
	comp[x] = cmp;
	for(int i = 0; i < grafosemponte[x].size(); i++){
		int viz = grafosemponte[x][i].first;
		if(comp[viz]) continue;
		dfssec(viz);
	}
}

vector<pair<int, int> > tree[MAXN];
int dp[MAXN][MAXK], hasup[MAXN], minlcup[MAXN], hasdown[MAXN], minlcdown[MAXN];
int tintree[MAXN], altura[MAXN] ,Tt;
int marctree[MAXN];
void dfstree(int x, int p){
	marctree[x] = 1;
	tintree[x] = ++Tt;
	minlcup[x] = minlcdown[x] = 1e9 + 7;
	dp[x][0] = p;
	for(int k = 1; k < MAXK; k++){
		dp[x][k] = dp[dp[x][k-1]][k-1];
	}
	for(int i = 0; i < tree[x].size(); i++){
		int viz = tree[x][i].first;
		if(viz == p) continue;
		altura[viz] = altura[x] + 1;
		dfstree(viz, x);
	}
}

void dfsprecalc(int x, int p){
	marctree[x] = 2;
	
	for(int i = 0; i < tree[x].size(); i++){
		int viz = tree[x][i].first;
		if(viz == p) continue;
		dfsprecalc(viz, x);
		hasdown[x] |= hasdown[viz];
		hasup[x] |= hasup[viz];
		if(hasup[viz]) minlcup[x] = min(minlcup[x], minlcup[viz]);
		if(hasdown[viz]) minlcdown[x] = min(minlcdown[x], minlcdown[viz]);
	}
}

void dfscalc(int x, int p){
	marctree[x] = 3;
	for(int i = 0; i < tree[x].size(); i++){
		int viz = tree[x][i].first;
		int id = tree[x][i].second;
		if(viz == p) continue;
		dfscalc(viz, x);
		//printf("AQU: %d %d %d\n", viz, minlcdown[viz], minlcup[viz]);
		if(hasup[viz] && minlcup[viz] <= tin[x]){
			edges[id].maketype(viz, x,1);
		}
		else if(hasdown[viz] && minlcdown[viz] <= tin[x]){
			edges[id].maketype(x, viz,1);
		}else{edges[id].maketype(0,0,1);}
	}
}

int lca(int u, int v){
	if(altura[u] < altura[v]) swap(u,v);
	int dist = altura[u] - altura[v];
	for(int k = 0; k < MAXK; k++){
		if(dist & (1<<k)) u = dp[u][k];
	}
	if(u == v) return u;
	for(int k = MAXK - 1; k >= 0; k--){
		if(dp[u][k] == dp[v][k]) continue;
		u = dp[u][k];
		v = dp[v][k];
	}
	return dp[u][0];
}
int n, m, p;
int main(){
	scanf("%d %d", &n, &m);
	for(int i = 1; i <= m; i++){
		int u, v;
		scanf("%d %d", &u, &v);
		edges[i].u = u;
		edges[i].v = v;
		grafo[u].push_back(make_pair(v, i));
		grafo[v].push_back(make_pair(u, i));
	}
	for(int i = 1; i <= n; i++){
		if(!marc[i]) dfsini(i, 0);
	}
	for(int i = 1; i <= m; i++){
		if(edges[i].tipo == 3){
			grafosemponte[edges[i].u].push_back(make_pair(edges[i].v, 0));
			grafosemponte[edges[i].v].push_back(make_pair(edges[i].u, 0));
		}
	}
	for(int i = 1; i <= n; i++){
		if(!comp[i])cmp++, dfssec(i);
	}
	for(int i = 0; i < bridge.size(); i++){
		int u = edges[bridge[i]].u;
		int v = edges[bridge[i]].v;
		tree[comp[u]].push_back(make_pair(comp[v], bridge[i]));
		tree[comp[v]].push_back(make_pair(comp[u], bridge[i]));
	}
	for(int i = 1; i <= cmp; i++){
		if(!marctree[i]) Tt = 0, dfstree(i, 0);
	}
	scanf("%d", &p);
	//memset(min)
	for(int i = 0; i < p; i++){
		int u, v;
		scanf("%d %d", &u, &v);
		if(comp[u] == comp[v]) continue;
		u = comp[u];
		v = comp[v];
		int lc = lca(u,v);
	//	printf("LC: %d %d %d\n",u, v, lc );
		if(lc == u){
			hasdown[v] = 1;
			minlcdown[v] = min(minlcdown[v], tintree[u]);
		}else if(lc == v){
			hasup[u] = 1;
			minlcup[u] = min(minlcup[u], tintree[v]);

		}else{
			hasdown[v] = 1;
			minlcdown[v] = min(minlcdown[v], tintree[lc]);
			hasup[u] = 1;
			minlcup[u] = min(minlcup[u], tintree[lc]);
		}
	}
	for(int i = 1; i <= cmp; i++){
		if(marctree[i] != 2) dfsprecalc(i, 0);
	}
	for(int i = 1; i <= cmp; i++){
		if(marctree[i] != 3) dfscalc(i, 0);
	}
	for(int i = 1; i <= m; i++){
		if(edges[i].tipo == 3 || edges[i].tipo == 0) printf("B");
		if(edges[i].tipo == 2) printf("L");
		if(edges[i].tipo == 1) printf("R");
	}
	printf("\n");

}

Compilation message

oneway.cpp: In function 'void dfsini(int, int)':
oneway.cpp:39:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |  for(int i = 0; i < grafo[x].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~~
oneway.cpp: In function 'void dfssec(int)':
oneway.cpp:54:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |  for(int i = 0; i < grafosemponte[x].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~~~~~~~~~~
oneway.cpp: In function 'void dfstree(int, int)':
oneway.cpp:73:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |  for(int i = 0; i < tree[x].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~
oneway.cpp: In function 'void dfsprecalc(int, int)':
oneway.cpp:84:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   84 |  for(int i = 0; i < tree[x].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~
oneway.cpp: In function 'void dfscalc(int, int)':
oneway.cpp:97:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   97 |  for(int i = 0; i < tree[x].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~
oneway.cpp: In function 'int main()':
oneway.cpp:149:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  149 |  for(int i = 0; i < bridge.size(); i++){
      |                 ~~^~~~~~~~~~~~~~~
oneway.cpp:128:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  128 |  scanf("%d %d", &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~~
oneway.cpp:131:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  131 |   scanf("%d %d", &u, &v);
      |   ~~~~~^~~~~~~~~~~~~~~~~
oneway.cpp:158:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  158 |  scanf("%d", &p);
      |  ~~~~~^~~~~~~~~~
oneway.cpp:162:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  162 |   scanf("%d %d", &u, &v);
      |   ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 7424 KB Output is correct
2 Correct 5 ms 7424 KB Output is correct
3 Correct 6 ms 7552 KB Output is correct
4 Correct 6 ms 7680 KB Output is correct
5 Correct 7 ms 7680 KB Output is correct
6 Correct 6 ms 7552 KB Output is correct
7 Correct 6 ms 7680 KB Output is correct
8 Correct 6 ms 7680 KB Output is correct
9 Correct 6 ms 7552 KB Output is correct
10 Correct 6 ms 7552 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 7424 KB Output is correct
2 Correct 5 ms 7424 KB Output is correct
3 Correct 6 ms 7552 KB Output is correct
4 Correct 6 ms 7680 KB Output is correct
5 Correct 7 ms 7680 KB Output is correct
6 Correct 6 ms 7552 KB Output is correct
7 Correct 6 ms 7680 KB Output is correct
8 Correct 6 ms 7680 KB Output is correct
9 Correct 6 ms 7552 KB Output is correct
10 Correct 6 ms 7552 KB Output is correct
11 Correct 62 ms 14344 KB Output is correct
12 Correct 76 ms 15736 KB Output is correct
13 Correct 91 ms 18000 KB Output is correct
14 Correct 121 ms 22776 KB Output is correct
15 Correct 121 ms 24308 KB Output is correct
16 Correct 166 ms 31084 KB Output is correct
17 Correct 185 ms 32372 KB Output is correct
18 Correct 159 ms 31088 KB Output is correct
19 Correct 173 ms 33524 KB Output is correct
20 Correct 79 ms 16376 KB Output is correct
21 Correct 72 ms 16248 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 7424 KB Output is correct
2 Correct 5 ms 7424 KB Output is correct
3 Correct 6 ms 7552 KB Output is correct
4 Correct 6 ms 7680 KB Output is correct
5 Correct 7 ms 7680 KB Output is correct
6 Correct 6 ms 7552 KB Output is correct
7 Correct 6 ms 7680 KB Output is correct
8 Correct 6 ms 7680 KB Output is correct
9 Correct 6 ms 7552 KB Output is correct
10 Correct 6 ms 7552 KB Output is correct
11 Correct 62 ms 14344 KB Output is correct
12 Correct 76 ms 15736 KB Output is correct
13 Correct 91 ms 18000 KB Output is correct
14 Correct 121 ms 22776 KB Output is correct
15 Correct 121 ms 24308 KB Output is correct
16 Correct 166 ms 31084 KB Output is correct
17 Correct 185 ms 32372 KB Output is correct
18 Correct 159 ms 31088 KB Output is correct
19 Correct 173 ms 33524 KB Output is correct
20 Correct 79 ms 16376 KB Output is correct
21 Correct 72 ms 16248 KB Output is correct
22 Correct 315 ms 33624 KB Output is correct
23 Correct 262 ms 31984 KB Output is correct
24 Correct 241 ms 32112 KB Output is correct
25 Correct 301 ms 36468 KB Output is correct
26 Correct 278 ms 33040 KB Output is correct
27 Correct 268 ms 31980 KB Output is correct
28 Correct 55 ms 11772 KB Output is correct
29 Correct 110 ms 17112 KB Output is correct
30 Correct 111 ms 17276 KB Output is correct
31 Correct 117 ms 17656 KB Output is correct
32 Correct 151 ms 23928 KB Output is correct