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Submission #588697

# Submission time Handle Problem Language Result Execution time Memory
588697 2022-07-03T21:41:12 Z peuch Event Hopping (BOI22_events) C++17
20 / 100
 82 ms 14016 KB 
#include<bits/stdc++.h>
using namespace std;

const int MAXN = 1e5 + 10;
const int INF = 1e9;

int n, q;
int s[MAXN], e[MAXN];
int ans[MAXN];

struct event{
	int s, e, id;
	event(int _s, int _e, int _id) {
		s = _s;
		e = _e;
		id = _id;
	}
	bool operator < (event x){
		if(e == x.e) return s < x.s;
		return e < x.e;
	}
};

struct query{
	int l, r, id;
	query(int _l, int _r, int _id){
		l = _l;
		r = _r;
		id = _id;
	}
};

vector<query> ar[MAXN];

vector<event> line;
int dist[MAXN];
int tam[MAXN];

vector<vector<int> > auxPoint;

int main(){
	scanf("%d %d", &n, &q);
	for(int i = 1; i <= n; i++){
		scanf("%d %d", &s[i], &e[i]);
		line.push_back(event(s[i], e[i], i));
	}
	for(int i = 1; i <= q; i++){
		int ini, fim;
		scanf("%d %d", &ini, &fim);
		ans[i] = INF;
		if(ini == fim) ans[i] = 0;
		else ar[fim].push_back(query(e[ini], e[fim], i));
	}
	
	sort(line.begin(), line.end());
	
	vector<int> pilha;
	for(int i = 0; i < line.size(); i++){
//		printf("Adding event: %d %d\n", line[i].s, line[i].e);
		while(!pilha.empty() && line[pilha.back()].s >= line[i].s){
			pilha.pop_back();
		}
		pilha.push_back(i);
		
		int ini = 0, fim = pilha.size() - 1;
		while(ini != fim){
			int mid = (ini + fim) >> 1;
			if(line[pilha[mid]].e >= line[i].s) fim = mid;
			else ini = mid + 1;
		}
//		printf("\t -> %d (%d)\n", pilha[ini], ini);
		ini = pilha[ini];
		if(i == ini){
			dist[i] = auxPoint.size();
			auxPoint.push_back(vector<int> (0));
		}
		else dist[i] = dist[ini];
		while(!auxPoint[dist[i]].empty() && auxPoint[dist[i]].back() > line[ini].s)
			auxPoint[dist[i]].pop_back();
		auxPoint[dist[i]].push_back(line[i].s);
		
//		printf("\t(%d) ", dist[i]);
//		for(int j = 0; j < auxPoint[dist[i]].size(); j++)
//			printf("%d ", auxPoint[dist[i]][j]);
//		printf("\n");
		for(int j = 0; j < ar[line[i].id].size(); j++){
//			printf("Query event: %d %d %d\n", ar[line[i].id][j].l, ar[line[i].id][j].r, ar[line[i].id][j].id);
			if(ar[line[i].id][j].l > ar[line[i].id][j].r) continue;
			int k = upper_bound(auxPoint[dist[i]].begin(), auxPoint[dist[i]].end(), ar[line[i].id][j].l) - auxPoint[dist[i]].begin() - 1;
//			printf("\t%d\n", k);
			if(k < 0) continue;
			ans[ar[line[i].id][j].id] = auxPoint[dist[i]].size() - k;
		}
//		for(int j = 0; j <= i; j++){
//			printf("dist[%d] = ", j);
//			for(int k = 0; k < auxPoint[dist[j]].size(); k++)
//				printf("%d ", auxPoint[dist[j]][k]);
//			printf("\n");
//		}
	}
	
	for(int i = 1; i <= q; i++){
		if(ans[i] == INF) printf("impossible\n");
		else printf("%d\n", ans[i]);
	}
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:58:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<event>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |  for(int i = 0; i < line.size(); i++){
      |                 ~~^~~~~~~~~~~~~
events.cpp:86:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<query>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |   for(int j = 0; j < ar[line[i].id].size(); j++){
      |                  ~~^~~~~~~~~~~~~~~~~~~~~~~
events.cpp:42:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |  scanf("%d %d", &n, &q);
      |  ~~~~~^~~~~~~~~~~~~~~~~
events.cpp:44:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |   scanf("%d %d", &s[i], &e[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~
events.cpp:49:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |   scanf("%d %d", &ini, &fim);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 72 ms 8476 KB Output is correct
3 Correct 70 ms 8896 KB Output is correct
4 Correct 76 ms 8740 KB Output is correct
5 Correct 68 ms 9392 KB Output is correct
6 Correct 68 ms 10172 KB Output is correct
7 Correct 72 ms 9992 KB Output is correct
8 Correct 69 ms 13976 KB Output is correct
9 Correct 67 ms 13916 KB Output is correct
10 Correct 76 ms 9636 KB Output is correct
11 Correct 82 ms 11708 KB Output is correct
12 Correct 53 ms 13236 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2644 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 2 ms 2644 KB Output is correct
9 Correct 2 ms 2748 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2644 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 2 ms 2644 KB Output is correct
9 Correct 2 ms 2748 KB Output is correct
10 Correct 1 ms 2644 KB Output is correct
11 Correct 1 ms 2644 KB Output is correct
12 Correct 2 ms 2644 KB Output is correct
13 Correct 2 ms 2644 KB Output is correct
14 Correct 2 ms 2644 KB Output is correct
15 Correct 2 ms 2644 KB Output is correct
16 Correct 2 ms 2644 KB Output is correct
17 Correct 2 ms 2644 KB Output is correct
18 Correct 2 ms 2644 KB Output is correct
19 Correct 31 ms 5408 KB Output is correct
20 Correct 32 ms 5416 KB Output is correct
21 Correct 35 ms 6172 KB Output is correct
22 Incorrect 31 ms 6328 KB Output isn't correct
23 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2644 KB Output is correct
2 Correct 1 ms 2644 KB Output is correct
3 Correct 2 ms 2644 KB Output is correct
4 Correct 2 ms 2644 KB Output is correct
5 Correct 2 ms 2644 KB Output is correct
6 Correct 2 ms 2644 KB Output is correct
7 Correct 2 ms 2644 KB Output is correct
8 Correct 2 ms 2644 KB Output is correct
9 Correct 2 ms 2748 KB Output is correct
10 Correct 1 ms 2644 KB Output is correct
11 Correct 1 ms 2644 KB Output is correct
12 Correct 2 ms 2684 KB Output is correct
13 Correct 2 ms 2772 KB Output is correct
14 Correct 2 ms 2644 KB Output is correct
15 Correct 2 ms 2644 KB Output is correct
16 Correct 2 ms 2684 KB Output is correct
17 Correct 2 ms 2644 KB Output is correct
18 Correct 2 ms 2644 KB Output is correct
19 Correct 40 ms 7756 KB Output is correct
20 Correct 38 ms 6492 KB Output is correct
21 Incorrect 40 ms 8356 KB Output isn't correct
22 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 67 ms 8384 KB Output is correct
2 Correct 69 ms 9076 KB Output is correct
3 Correct 74 ms 8740 KB Output is correct
4 Correct 73 ms 14016 KB Output is correct
5 Correct 79 ms 9660 KB Output is correct
6 Incorrect 73 ms 9036 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2644 KB Output is correct
2 Correct 72 ms 8476 KB Output is correct
3 Correct 70 ms 8896 KB Output is correct
4 Correct 76 ms 8740 KB Output is correct
5 Correct 68 ms 9392 KB Output is correct
6 Correct 68 ms 10172 KB Output is correct
7 Correct 72 ms 9992 KB Output is correct
8 Correct 69 ms 13976 KB Output is correct
9 Correct 67 ms 13916 KB Output is correct
10 Correct 76 ms 9636 KB Output is correct
11 Correct 82 ms 11708 KB Output is correct
12 Correct 53 ms 13236 KB Output is correct
13 Correct 1 ms 2644 KB Output is correct
14 Correct 1 ms 2644 KB Output is correct
15 Correct 2 ms 2644 KB Output is correct
16 Correct 2 ms 2644 KB Output is correct
17 Correct 2 ms 2644 KB Output is correct
18 Correct 2 ms 2644 KB Output is correct
19 Correct 2 ms 2644 KB Output is correct
20 Correct 2 ms 2644 KB Output is correct
21 Correct 2 ms 2748 KB Output is correct
22 Correct 1 ms 2644 KB Output is correct
23 Correct 1 ms 2644 KB Output is correct
24 Correct 2 ms 2644 KB Output is correct
25 Correct 2 ms 2644 KB Output is correct
26 Correct 2 ms 2644 KB Output is correct
27 Correct 2 ms 2644 KB Output is correct
28 Correct 2 ms 2644 KB Output is correct
29 Correct 2 ms 2644 KB Output is correct
30 Correct 2 ms 2644 KB Output is correct
31 Correct 31 ms 5408 KB Output is correct
32 Correct 32 ms 5416 KB Output is correct
33 Correct 35 ms 6172 KB Output is correct
34 Incorrect 31 ms 6328 KB Output isn't correct
35 Halted 0 ms 0 KB -