loj#2312. 「HAOI2017」八纵八横(线性基 线段树分治)

题意

题目链接

Sol

线性基+线段树分治板子题。。

调起来有点自闭。。

#include<bits/stdc++.h> 
#define fi first
#define se second
#define pb push_back 
#define bit bitset<B + 1> 
using namespace std;
const int MAXN = 501,  B = 1001, SS = 4001;
inline int read() {
    char c = getchar(); int x = 0, f = 1;
    while(c < '0' || c > '9') {if(c == '-') f = -1; c = getchar();}
    while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
    return x * f;
}
int N, M, Q, las[SS];
struct Graph {
	struct Edge {
		int u, v;
		bit w;
		int nxt;
	}E[3021];
	int head[MAXN], num, vis[MAXN];
	Graph() {
		memset(head, -1, sizeof(head));
		memset(vis, 0, sizeof(vis));
		num = 0;
	}
	bit P[B + 1], dis[MAXN];
	void insert(bit s) {
		for(int i = B; ~i; i--) {
			if(s[i]) {
				if(!P[i].count()) {P[i] = s; break;}
				s = s ^ P[i];
			}
		}
	}
	void dfs(int x, int fa) {
		vis[x] = 1;
		for(int i = head[x]; ~i; i = E[i].nxt) {
			int to = E[i].v; bit w = E[i].w;
			if((i ^ 1) == fa) continue;
			if(vis[to]) insert(dis[x] ^ dis[to] ^  w);
			else {
				dis[to] = dis[x] ^ w; 
				dfs(to, i);
			}
		}
	}
	void Query() {
		bit ans; ans.reset();
		for(int i = B; ~i; i--) if(ans[i] ^ (P[i][i])) ans ^= P[i];
		for(int i = B; ~i; i--) 
			if(ans[i]) {
				for(int j = i; ~j; j--) cout << ans[j];
				puts("");
				return ;
			}	
		puts("0");
	}
	void AddEdge(int x, int y, bit w) {
		E[num] = {x, y, w, head[x]};
		head[x] =num++;
	}
	void Insert(int x, int y, bit w) {
		insert(dis[x] ^ dis[y] ^ w);
	}

}bg;
struct Edge {
	int u, v;
	bit w;
}e[SS];
vector<Edge> tag[SS];

#define ls k << 1
#define rs k << 1 | 1
void Add(int k, int l, int r, int ql, int qr, Edge v) {
	if(ql > qr) return ;
	if(ql <= l && r <= qr) {tag[k].pb(v); return ;}
	int mid = l + r >> 1;
	if(ql <= mid) Add(ls, l, mid, ql, qr, v);
	if(qr  > mid) Add(rs, mid + 1, r, ql, qr, v);
}
void Down(int k, int l, int r, Graph now) {
	if(l > r) return ;
	Graph nxt = now;
	for(auto flag: tag[k]) 
		nxt.Insert(flag.u, flag.v, flag.w);
	if(l == r) {
		nxt.Query(); 
		return ;
	}
	int mid = l + r >> 1;
	Down(ls, l, mid, nxt);
	Down(rs, mid + 1, r, nxt);
}
signed main() {
	N = read(); M = read(); Q = read();
	for(int i = 1; i <= M; i++) {
		int x = read(), y = read(); bit w; cin >> w;
		bg.AddEdge(x, y, w);
		bg.AddEdge(y, x, w);
	}
	memset(las, -1, sizeof(las));
	int youducuotile = 0;
	for(int i = 1; i <= Q; i++) {
		char opt[10]; scanf("%s", opt + 1);
		if(opt[1] == 'A') {
			e[++youducuotile ].u = read(), e[youducuotile ].v = read();
			cin >> e[youducuotile ].w; las[youducuotile ] = i;
		} else if(opt[1] == 'C' && opt[2] == 'a') {
			int k = read(); 
			Add(1, 1, Q, las[k], i - 1, e[k]); 
			las[k] = -1;
		} else {
			int k = read();
			Add(1, 1, Q, las[k], i - 1, e[k]);
			cin >> e[k].w;
			las[k] = i;
		}
	}
	for(int i = 1; i <= Q; i++)
		if(~las[i])
			Add(1, 1, Q, las[i], Q, e[i]);
	bg.dfs(1, -1);
	bg.Query();
	if(Q) 
		Down(1, 1, Q, bg);
    return 0;
}

标签：nxt,loj,八横,2312,mid,int,read,define,las
来源： https://blog.51cto.com/u_15239936/2868840