Submission #41554

#	Time	Username	Problem	Language	Result	Execution time	Memory
41554		Pajaraja	Birthday gift (IZhO18_treearray)	C++14	100 / 100	1479 ms	262144 KiB

treearray

#include <bits/stdc++.h>
#define MAXN 200007
#define MAXL 22
using namespace std;
vector<int> g[MAXN];
multiset<int> k[MAXN],km[MAXN];
multiset<int>::iterator it;
int p[MAXL][MAXN],a[MAXN],b[MAXN],in[MAXN],out[MAXN],n,cnt;
void dfs(int s,int f)
{
	p[0][s]=f;
	in[s]=cnt++;
	for(int i=0;i<g[s].size();i++) if(g[s][i]!=f) dfs(g[s][i],s);
	out[s]=cnt++;
}
bool insub(int x,int y) {return ((in[x]<=in[y])&&(out[x]>=out[y]));}
void lcainit()
{
	dfs(1,0);
	in[0]=-1;
	out[0]=2*MAXN;
	for(int i=1;i<MAXL;i++) for(int j=1;j<=n;j++) p[i][j]=p[i-1][p[i-1][j]];
}
int lca(int x,int y)
{
	if(insub(x,y)) return x;
	if(insub(y,x)) return y;
	for(int i=MAXL-1;i>=0;i--) if(!insub(p[i][x],y)) x=p[i][x];
	return p[0][x];
}
int main()
{
	int m,q;
	scanf("%d%d%d",&n,&m,&q);
	for(int i=0;i<n-1;i++)
	{
		int t1,t2;
		scanf("%d%d",&t1,&t2);
		g[t1].push_back(t2);
		g[t2].push_back(t1);
	}
	lcainit();
	for(int i=1;i<=m;i++) scanf("%d",&a[i]);
	for(int i=1;i<m;i++) b[i]=lca(a[i],a[i+1]);
	for(int i=1;i<=m;i++) k[a[i]].insert(i);
	for(int i=1;i<m;i++) km[b[i]].insert(i);
	while(q--)
	{
		int t;
		scanf("%d",&t);
		if(t==1)
		{
			int t1,t2;
			scanf("%d%d",&t1,&t2);
			if(t1>1)
			{
				int u=lca(t2,a[t1-1]);
				km[b[t1-1]].erase(t1-1);	
				km[u].insert(t1-1);
				b[t1-1]=u;
			}
			if(t1<m)
			{
				int u=lca(t2,a[t1+1]);
				km[b[t1]].erase(t1);	
				km[u].insert(t1);
				b[t1]=u;
			}
			k[a[t1]].erase(t1);
			a[t1]=t2;
			k[a[t1]].insert(t1);
		}
		else
		{
			int l,r,u;
			scanf("%d%d%d",&l,&r,&u);
			it=k[u].lower_bound(l);
			if(it!=k[u].end() && *it<=r) {printf("%d %d\n",*it,*it); continue;}
			it=km[u].lower_bound(l);
			if(it!=km[u].end() && *it<r) {printf("%d %d\n",*it,*it+1); continue;}
			printf("-1 -1\n");
		}
	}
}

Compilation message (stderr)

treearray.cpp: In function 'void dfs(int, int)':
treearray.cpp:13:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<g[s].size();i++) if(g[s][i]!=f) dfs(g[s][i],s);
               ^
treearray.cpp: In function 'int main()':
treearray.cpp:34:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d",&n,&m,&q);
                          ^
treearray.cpp:38:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&t1,&t2);
                        ^
treearray.cpp:43:41: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1;i<=m;i++) scanf("%d",&a[i]);
                                         ^
treearray.cpp:50:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&t);
                 ^
treearray.cpp:54:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d%d",&t1,&t2);
                         ^
treearray.cpp:76:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d%d%d",&l,&r,&u);
                            ^

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 26 / 26
• Subtask 4: 44 / 44