J Red-Black Paths(ICPC网络赛第一场)

Posted 2021-10-12 Jozky86

J Red-Black Paths(ICPC网络赛第一场)

题意：

有n个点，m次操作，有三种操作：
1 u v：从u向v建一个有向边
2 u：将点u染成红色
3 u: 将点u染成黑色
4 查询最新生成的红黑边的异或值
红黑边的值为：${\sum }_{1<=i<=length(path)}{n}_i\ast i$

题解：

代码：

#include <bits/stdc++.h>
#include <unordered_map>
#define debug(a, b) printf("%s = %d\\n", a, b);
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> PII;
clock_t startTime, endTime;
//Fe~Jozky
const ll INF_ll= 1e18;
const int INF_int= 0x3f3f3f3f;
void read(){};
template <typename _Tp, typename... _Tps> void read(_Tp& x, _Tps&... Ar)
{
    x= 0;
    char c= getchar();
    bool flag= 0;
    while (c < '0' || c > '9')
        flag|= (c == '-'), c= getchar();
    while (c >= '0' && c <= '9')
        x= (x << 3) + (x << 1) + (c ^ 48), c= getchar();
    if (flag)
        x= -x;
    read(Ar...);
}
template <typename T> inline void write(T x)
{
    if (x < 0) {
        x= ~(x - 1);
        putchar('-');
    }
    if (x > 9)
        write(x / 10);
    putchar(x % 10 + '0');
}
void rd_test()
{
#ifdef ONLINE_JUDGE
#else
    startTime = clock ();
    freopen("data.in", "r", stdin);
#endif
}
void Time_test()
{
#ifdef ONLINE_JUDGE
#else
    endTime= clock();
    printf("\\nRun Time:%lfs\\n", (double)(endTime - startTime) / CLOCKS_PER_SEC);
#endif
}
const int maxn=5e6+9;
vector<int>Q;
vector<int>R;
int black[maxn];
int red[maxn];
struct edge{
	int u,v,tim;
};
vector<edge>e;
vector<PII>vec[maxn];
int vis[maxn];
int tag[maxn];
ll ans[maxn];
void dfs(int u){
	vis[u]=1;
	if(black[u])tag[u]=1;
	for(auto it:vec[u]){
		int v=it.first;
		int w=it.second;
		if(vis[v]){
			tag[u]|=tag[v];
			continue;
		}
		dfs(v);
		tag[u]|=tag[v];
	}
}
void rebuild(){
	for(int i=0;i<=5000000;i++)vec[i].clear();
	for(auto it:e){
		if(tag[it.u]&tag[it.v]){
			vec[it.u].push_back({it.v,it.tim});
		}
	}
}
void path(int u,int maxx,ll sum,int dep){
	if(black[u]){
		int tim=max(maxx,black[u]);
		ans[tim]^=sum;
	}
	for(auto it:vec[u]){
		int v=it.first;
		int tim=it.second;
		path(v,max(maxx,tim),sum+1ll*dep*v,dep+1);
	}
	
}
int main()
{
    rd_test();
	int n;
	read(n);
	for(int i=1;i<=n;i++){
		int  op,u,v;
		read(op);
		if(op==1){
			read(u,v);
			vec[u].push_back({v,i});
			e.push_back({u,v,i});
		}
		else if(op==2){
			int u;
			cin>>u;
			R.push_back(u);
			red[u]=i;
		}
		else if(op==3){
			cin>>u;
			black[u]=i;
		}
		else if(op==4){
			Q.push_back(i);
		}
	}
	for(auto v:R){
		if(!vis[v])
			dfs(v); 
	}
	rebuild();
	for(auto v:R){
		path(v,red[v],1ll*v,2);
	}
	for(int i=1;i<=n;i++)ans[i]^=ans[i-1];
	ll res=0;
	for(int i=0;i<Q.size();i++){
		res=ans[Q[i]];
		if(i) res^=ans[Q[i-1]];
		cout<<res<<endl;
	}
	return 0;
    //Time_test();
}