#include <stdio.h>
#include <map>
#include <queue>
#include <set>
#include <vector>
using namespace std;
int situ_count, goal_num;
vector<vector<int> > graph;
vector<int> dijkstra(int v, int src){
vector<int> dist(v+1,987654321);
dist[src] = 0;
priority_queue<pair<int,int> > p_que;
p_que.push(make_pair(0,src));
while(!p_que.empty()){
int cost = -p_que.top().first;
int here = p_que.top().second;
p_que.pop();
if(cost > dist[here]){
continue;
}
for(int i=0;i<graph[here].size();i++){
int there = graph[here][i];
int nextDist = cost + 1;
if(dist[there] > nextDist){
dist[there] = nextDist;
p_que.push(make_pair(-nextDist,there));
}
}
}
return dist;
}
int main(void){
scanf("%d%d", &goal_num, &situ_count);
graph.resize(goal_num+1);
for(int i=0; i<=goal_num; i++){
graph[i].resize(goal_num+1, 0);
}
int tmpa, tmpb;
for(int i=0; i<situ_count; i++){
scanf("%d%d", &tmpa, &tmpb);
graph[tmpa].push_back(tmpb);
}
vector<int> dist_vec = dijkstra(goal_num, 1);
if(dist_vec[goal_num] == 987654321){
printf("-1\n");
}
else{
printf("%d\n", dist_vec[goal_num]);
}
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
1244 KB |
Output is correct |
2 |
Correct |
0 ms |
1244 KB |
Output is correct |
3 |
Correct |
0 ms |
1244 KB |
Output is correct |
4 |
Correct |
0 ms |
1244 KB |
Output is correct |
5 |
Correct |
0 ms |
1244 KB |
Output is correct |
6 |
Correct |
0 ms |
1244 KB |
Output is correct |
7 |
Correct |
0 ms |
1244 KB |
Output is correct |
8 |
Correct |
0 ms |
1244 KB |
Output is correct |
9 |
Correct |
0 ms |
1244 KB |
Output is correct |
10 |
Correct |
12 ms |
1908 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Memory limit exceeded |
56 ms |
262144 KB |
Memory limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |