num++

return

++left

--right

i=j

 j++

j=i

 j--

solve(j,right,deep+1)

solve(j+1,right,deep+1)

solve(left,j,deep+1)

solve(left,j-1,deep+ 1)

solve(left,j,deep+1)

solve(j+1,right,deep+1)

solve(j,right,deep+1)

solve(left,j-1,deep+1)

cur<upper bound

cur<=upper bound

cur>upper bound

cur>=upper bound

left child

right child

alroot].left child

alroot .right child

left child

right child

cur+1

cur

left child

upper bound-1

right child

upper bound

-1

0

1

2

v=0

v=-1

dis[v]=1

dis[v]=0

dist[v]!--1

v==n-1

used[i]!=1

dist[i]<=dist[v]

used[i]=1

used[v]=1

v++

v=i

w[v][v]=0

 w[v][v]=1

used[v]=1

dist[v]++

 !used[v]

!used[i]

dist[v]-dist[i]+ (used[i]==1)<=w[v][i]

dist[v]+w[v][i]<=dist[i]

graph[b][a]=1;

degree[b]=degree[b]+1

degree[b]=degree[a]+1

graph[b][a]=graph[a][b]+1

graph[1][i]!=0

graph[1][i]==0

degree[i]==0

degree[i]!=0

 degree[i]--

head+ +

tail--

tail++

graph[queue[head]][i]++

tail-=head

graph[queue[tail]][i]==1

++head

 ans+ 1<len[a]

ans<len[a]

len[a]-1>=ans

!ans

dist[1]=1

dist[n]=1

dist[1]=-1

dist[1]=0

dist[point[x]]+weight[j]<dist[x]

dist[j]+weight[x]<dist[point[x]]

dist[x]+weight[j]<dist[point[j]]

dist[x]+weight[point[j]]<dist[j]

t--

visit[x]=0

point[j]=j

nxt[j]=point[j]

dist[x]+weight[j]--dist[point[j]]

dist[x]+weight[point[j]]==dist[point[j]]

dist[x]+weight[point[j]]==dist[point[x]]

dist[point[x]]+weight[point[j]]==dist[point[j]]

visit[point[j]]=0

visit[point[j]]=0

visit[queue[t]]=1

visit[point[j]]=1