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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#84383 | #5651. Parmigiana With Seafood | Pdw2007 | WA | 2ms | 3676kb | C++14 | 1.0kb | 2023-03-06 14:12:20 | 2023-03-06 14:12:23 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
const int N=1e5+5;
int n,ans;
int tot,head[N];
struct edge{
int to,nxt;
}e[N<<1];
int d[N],mx;
void add(int x,int y) {
tot++;
e[tot].to=y;e[tot].nxt=head[x];head[x]=tot;
return;
}
int mx1,mx2,mx3;
void dfs(int x,int fa) {
d[x]=d[fa]+1;
if(d[x]&1) mx=max(mx,x);
else if(x!=n) {
if(x>mx1) mx3=mx2,mx2=mx1,mx1=x;
else if(x>mx2) mx3=mx2,mx2=x;
else if(x>mx3) mx3=x;
}
int koishi=0;
for(int i=head[x];i;i=e[i].nxt) {
int to=e[i].to;
if(to==fa) continue;
dfs(to,x);
koishi++;
}
if(!koishi) ans=max(ans,x);
if(koishi==1&&fa==0) ans=max(ans,x);
return;
}
int main() {
scanf("%d",&n);
for(int i=1,x,y;i<n;i++) {
scanf("%d%d",&x,&y);
add(x,y);add(y,x);
}
if(!(n&1)) {
printf("%d",n);
return 0;
}
d[0]=-1;
dfs(n,0);
// ans=max(ans,mx);
ans=max(ans,mx3);
printf("%d\n",ans);
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 2ms
memory: 3676kb
input:
4 1 2 1 3 1 4
output:
4
result:
ok single line: '4'
Test #2:
score: -100
Wrong Answer
time: 0ms
memory: 3560kb
input:
5 1 5 5 3 3 4 4 2
output:
2
result:
wrong answer 1st lines differ - expected: '3', found: '2'