Cut itof~ You↑ have↓ get↗lost~~

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百度~优先搜索~ mythware_super_password 这是个病句↓

I am the storm that is aproaching!!!!!!!!!!!!!!!

Manbow~~~ WOW!! Duang~↑↓

我是Halanfus的狗🌹

I·······接下一句； I am the storm that is Aproaching!~!!!!!;

I am FIRE!🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥😡🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥😡🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥😡🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥😡🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥

Burn those who dare to care for me~╰（‵□′）╯😈

fly brocken wings;

I know;

you are steel with me;

I need is a nudge to get me started~;

I wanted blood😭;

I wanted Black↓👿 and White↑😇；

I~Must↑be→the↘↗reathen↗↘↓why↓~↑→😭😥；

You must given up your smiles😡!;

Q:我为什么要在主页整这么抽象的活？

A:因为打字真的很豪玩😎；

Halanfus意义明确的单向图深搜啊🍬🍬🌷ψ(._. )>

#include<bits/stdc++.h>
//Halanfus到此一游§(*￣▽￣*)§
using namespace std;
int n,m,a,b;
bool reach,ed[200007];
vector<vector<int> > v(200000);
void dfs(int r){
    if(ed[r]) return;
    ed[r]=true;
    if(!v[r].size()) return;
    if(!reach){
    int s=v[r].size();
    for(int i=0;i<s;i+=1){
        if(v[r][i]==b){
            reach=true;
            return;
        }
        else dfs(v[r][i]);
    }
    }
    else return;
}
int main(){
    cin>>n>>m>>a>>b;
    int x,y;
    for(int i=1;i<=m;i+=1){
        cin>>x>>y;
        v[x].push_back(y);
    }
    dfs(a);
    if(reach) cout<<"Yes";
    else cout<<"No";

return 0;
}

二叉树的前中后综合遍历，试卷上看到的，好用优化一下就搬过来了🍧🍨🍩

#include<bits/stdc++.h>
using namespace std;
int a[101][3];
bool b[101];
void dfs(int k,int w){
	if(w==1) cout<<k<<" ";//前 
	if(a[k][1]) dfs(a[k][1],w);
	if(w==2) cout<<k<<" ";//后 
	if(a[k][2]) dfs(a[k][2],w);
	if(w==3) cout<<k<<" ";//中 
}
int main(){
	int n,m,t,root;
	cin>>n;
	for(int i=1;i<=n;i+=1){
		cin>>t;
		cin>>a[t][1]>>a[t][2];
		b[a[t][1]]=1;
		b[a[t][2]]=1;
	}
	for(int i=1;i<=n;i+=1){
		if(b[i]==0){
			root=i;
			break;
		}
	}
	dfs(root,1);
	cout<<endl;
	dfs(root,2);
	cout<<endl;
	dfs(root,3);
	cout<<endl;
	return 0;
}