#include<stdio.h>
int n, m, dist[222222];
int top[111111], endp[222222], prv[222222], ecn;
int fr, rr, que[222222];
int main(){
int i, s, e;
scanf("%d%d", &n, &m);
for(i=1; i<=n; i++)top[i]=-1, dist[i]=-1;
for(i=0; i<m; i++){
scanf("%d%d", &s, &e);
endp[ecn]=e, prv[ecn]=top[s], top[s]=ecn++;
}
que[rr++]=1, dist[1]=0;
for(;fr<rr;fr++){
s=que[fr];
for(i=top[s]; i>=0; i=prv[i]){
e=endp[i];
if(dist[e]==-1){
dist[e]=dist[s]+1;
que[rr++]=e;
}
}
}
printf("%d", dist[n]);
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
4992 KB |
Output is correct |
2 |
Correct |
0 ms |
4992 KB |
Output is correct |
3 |
Correct |
0 ms |
4992 KB |
Output is correct |
4 |
Correct |
0 ms |
4992 KB |
Output is correct |
5 |
Correct |
0 ms |
4992 KB |
Output is correct |
6 |
Correct |
0 ms |
4992 KB |
Output is correct |
7 |
Correct |
0 ms |
4992 KB |
Output is correct |
8 |
Correct |
0 ms |
4992 KB |
Output is correct |
9 |
Correct |
0 ms |
4992 KB |
Output is correct |
10 |
Correct |
20 ms |
4992 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
4992 KB |
Output is correct |
2 |
Correct |
20 ms |
4992 KB |
Output is correct |
3 |
Correct |
40 ms |
4992 KB |
Output is correct |
4 |
Correct |
40 ms |
4992 KB |
Output is correct |
5 |
Correct |
36 ms |
4992 KB |
Output is correct |
6 |
Correct |
24 ms |
4992 KB |
Output is correct |
7 |
Correct |
28 ms |
4992 KB |
Output is correct |
8 |
Correct |
56 ms |
4992 KB |
Output is correct |
9 |
Correct |
32 ms |
4992 KB |
Output is correct |
10 |
Correct |
48 ms |
4992 KB |
Output is correct |