Submission #2182343

---

Source Code Expand

#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
#define ref(i,x,y)for(int i=x;i<=y;++i)
const int N=100001;
int n,m,cnt,res,head[N],du[N],q[N],t[N];
struct edge{int to,nxt;}e[N*2];
vector<int>s[N];bool vis[N];
bool cmp(int a,int b){return a>b;}
void add(int x,int y){e[++cnt]=(edge){y,head[x]};head[x]=cnt;}
int main(){
	scanf("%d",&n);
	ref(i,2,n){
		int x,y;scanf("%d%d",&x,&y);
		add(x,y),add(y,x);du[x]++,du[y]++;
	}
	res=1;
	ref(i,1,n)if(du[i]==1)q[++m]=i;
	ref(i,1,n){
		int x=q[i];vis[x]=1;
		if(s[x].empty())s[x].push_back(1);else{
			int p=0,r=1,sz=s[x].size()-1;
			if(t[x]>1){
				sort(s[x].begin(),s[x].end(),cmp);
				ref(i,1,sz)if(s[x][i]==s[x][i-1]){p=i;break;}
				if(p){
					r=s[x][p]+1;
					while(sz>=p-1)s[x].pop_back(),sz--;
				}
			}
			while(sz>=0&&s[x][sz]==r)s[x].pop_back(),r++,sz--;
			s[x].push_back(r);if(r>res)res=r;
		}
		int sz=s[x].size()-1;
		for(int j=head[x];j;j=e[j].nxt){
			int y=e[j].to;
			if(!vis[y]){
				ref(I,0,sz)s[y].push_back(s[x][I]);
				du[y]--;t[y]++;if(du[y]==1)q[++m]=y;
			}
		}
	}
	printf("%d\n",res-1);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:13:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
./Main.cpp:15:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   int x,y;scanf("%d%d",&x,&y);
                              ^

Judge Result