2020/8/26
英语四级
学习了kruskal重构树+dfs板的lca
mad dfs的lca竟然会快一点
#include"stdio.h"
#include"string.h"
#include"stack"
#include"map"
#include"math.h"
#include"iostream"
#include"vector"
#include"queue"
#include"algorithm"
using namespace std;
#pragma GCC optimize(2)
inline int read() {
int x = 0;
bool f = 1;
char c = getchar();
for (; !isdigit(c); c = getchar())
if (c == '-')
f = 0;
for (; isdigit(c); c = getchar()) x = (x << 3) + (x << 1) + c - '0';
if (f)
return x;
return 0 - x;
}
const int N = 300100;
const int mod = 1e9 + 7;
typedef struct Node{
int x,y,w;
}Node;
Node node[N];
int head[N],ver[N << 1],Next[N << 1],Edge[N << 1],tot;
int n,m,top;
int far[N],w[N];
int A,B,C,P;
int k,t;
int id[N],d[N];
int f[N][20];
int lg[N];
inline int rnd(){return A=(A*B+C)%P;}
inline void add(int x,int y){
ver[++ tot] = y; Next[tot] = head[x]; head[x] = tot;
}
bool cmp(Node a,Node b){
return a.w < b.w;
}
inline int Find(int x){
if(!far[x]) return x;
return far[x] = Find(far[x]);
}
/*
inline void bfs(int x){
queue<int> Q;Q.push(x);
d[x] = 1;
while(!Q.empty()){
int x = Q.front(); Q.pop();
for(int i = head[x]; i; i = Next[i]){
int y = ver[i];
if(d[y]) continue;
d[y] = d[x] + 1;
f[y][0] = x;
for(int j = 1; j <= t; j ++)
f[y][j] = f[f[y][j - 1]][j - 1];
Q.push(y);
}
}
}
inline int lca(int x,int y){
if(d[x] > d[y]) x ^= y ^= x ^= y;
for(int i = t; i >= 0; i --)
if(d[f[y][i]] >= d[x]) y = f[y][i];
if(x == y) return x;
for(int i = t; i >= 0; i --)
if(f[x][i] != f[y][i]) x = f[x][i],y = f[y][i];
return f[x][0];
}*/
void dfs(int cur, int fath) {
f[cur][0] = fath; d[cur] = d[fath] + 1;
for (int i = 1; i <= lg[d[cur]]; ++i)
f[cur][i] = f[f[cur][i - 1]][i - 1];
for (int i = head[cur]; i ; i = Next[i])
if (ver[i] != fath)
dfs(ver[i], cur);
}
int lca(int x, int y) {
if (d[x] < d[y]) swap(x, y);
while (d[x] > d[y])
x = f[x][lg[d[x] - d[y]] - 1];
if (x == y)
return x;
for (int i = lg[d[x]] - 1; i >= 0; --i)
if (f[x][i] != f[y][i])
x = f[x][i], y = f[y][i];
return f[x][0];
}
int main(){
n = read(); m = read();
for(int i = 1; i <= m; i ++){
node[i].x = read(); node[i].y = read();node[i].w = read();
}
sort(node + 1,node + m + 1,cmp);
top = n;
for(int i = 1; i <= m; i ++){
int x = node[i].x,y = node[i].y;
int fx = Find(x),fy = Find(y);
if(fx == fy) continue;
w[++ top] = node[i].w;
add(top,fx); //add(fx,top);
add(top,fy); //add(fy,top);
far[fx] = top;
far[fy] = top;
if(top == 2 * n - 1) break;
}
for (int i = 1; i < N; ++i)
lg[i] = lg[i - 1] + (1 << lg[i - 1] == i);
dfs(top, 0);
int q = read();
A = read(); B = read(); C = read(); P = read();
int s = 0;
while(q --){
int u=rnd()%n+1,v=rnd()%n+1;
int fa = lca(u,v);
if(u != v)
s += w[fa];
if(s >= mod) s -= mod;
}
printf("%d\n",s);
}
/*
3
1 2 3
2
2 6
*/
#include"stdio.h"
#include"string.h"
#include"stack"
#include"map"
#include"math.h"
#include"iostream"
#include"vector"
#include"queue"
#include"algorithm"
using namespace std;
typedef pair<int,int> PII;
inline int read(){
int s = 0, w = 1; char ch = getchar();
while(ch < '0' || ch > '9') { if(ch == '-') w = -1; ch = getchar(); }
while(ch >= '0' && ch <= '9') { s = (s << 3) + (s << 1) + (ch ^ 48); ch = getchar(); }
return s * w;
}
const int N = 300100;
int head[N],ver[N << 1],Next[N << 1],Edge[N << 1],tot;
int n,m;
int visit[N],match[N];
void add(int x,int y){
ver[++ tot] = y; Next[tot] = head[x]; head[x] = tot;
}
bool dfs(int x){
for(int i = head[x]; i; i = Next[i]){
int y = ver[i];
if(visit[y]) continue;
visit[y] = 1;
if(!match[y] || dfs(match[y])){
match[y] = x; return true;
}
}
return false;
}
int main(){
int T = read();
while(T --){
n = read(); m = read();
tot = 0;
memset(head,0,sizeof(head));
memset(match,0,sizeof(match));
for(int i = 1; i <= m; i ++){
int x = read(),y = read();
add(x,y + n);
}
int ans = 0;
for(int i = 1; i <= n + n; i ++){
memset(visit,0,sizeof(visit));
if(dfs(i)) ans ++;
}
//ans /= 2;
printf("%d\n",n - ans);
}
}
/*
3
1 2 3
2
2 6
*/
#include"stdio.h"
#include"string.h"
#include"stack"
#include"map"
#include"math.h"
#include"iostream"
#include"vector"
#include"queue"
#include"algorithm"
using namespace std;
#pragma GCC optimize(2)
inline int read() {
int x = 0;
bool f = 1;
char c = getchar();
for (; !isdigit(c); c = getchar())
if (c == '-')
f = 0;
for (; isdigit(c); c = getchar()) x = (x << 3) + (x << 1) + c - '0';
if (f)
return x;
return 0 - x;
}
const int N = 300100;
const int mod = 1e9 + 7;
typedef struct Node{
int x,y,w;
}Node;
Node node[N * 3];
int head[N],ver[N << 1],Next[N << 1],Edge[N << 1],tot;
int n,m,top;
int far[N],w[N];
int high[N],b[N],len;
int k,t;
int id[N],d[N];
int f[N][20];
int lg[N];
int root[N << 5],sum[N << 5],lc[N << 5],rc[N << 5],tot1;
int son[N][2],num,h[N],tt;
inline void add(int x,int y){
ver[++ tot] = y; Next[tot] = head[x]; head[x] = tot;
}
bool cmp(Node a,Node b){
return a.w < b.w;
}
inline int Find(int x){
if(!far[x]) return x;
return far[x] = Find(far[x]);
}
void dfs(int cur, int fath) {
f[cur][0] = fath; d[cur] = d[fath] + 1;
for (int i = 1; i <= lg[d[cur]]; ++i)
f[cur][i] = f[f[cur][i - 1]][i - 1];
for (int i = head[cur]; i ; i = Next[i])
if (ver[i] != fath)
dfs(ver[i], cur);
}
void Build_Tree(int &rt,int l,int r){
rt = ++ tot1; sum[rt] = 0;
if(l == r) return ;
int mid = (l + r) >> 1;
Build_Tree(lc[rt],l,mid);
Build_Tree(rc[rt],mid + 1,r);
}
void Update(int pre,int &rt,int l,int r,int v){
rt = ++ tot1;
lc[rt] = lc[pre]; rc[rt] = rc[pre]; sum[rt] = sum[pre] + 1;
if(l == r) return ;
int mid = (l + r) >> 1;
if(mid >= v) Update(lc[pre],lc[rt],l,mid,v);
else Update(rc[pre],rc[rt],mid + 1,r,v);
}
int query(int u,int v,int l,int r,int k){
int mid = (l + r) >> 1;
int x = sum[rc[v]] - sum[rc[u]];
// printf("v = %d u = %d l = %d r = %d k = %d x = %d\n",v,u,l,r,k,x);
if(l == r) {
if(k - (sum[v] - sum[u]) == 0)
return l;
return 0;
}
if(x >= k) return query(rc[u],rc[v],mid + 1,r,k);
else return query(lc[u],lc[v],l,mid,k - x);
}
void dfs1(int x,int far){
son[x][0] = num;
if(head[x] == 0){
son[x][0] = ++ num;
int id = lower_bound(b + 1,b + len + 1,high[x]) - b;
h[++ tt] = id;
return ;
}
for(int i = head[x]; i; i = Next[i]){
int y = ver[i];
if(far == y) continue;
dfs1(y,x);
}
son[x][1] = num;
}
int main(){
n = read(); m = read(); int q = read();
for(int i = 1; i <= n; i ++) b[i] = high[i] = read();
sort(b + 1,b + n + 1);
len = unique(b + 1,b + n + 1) - b - 1;
for(int i = 1; i <= m; i ++){
node[i].x = read(); node[i].y = read();node[i].w = read();
}
sort(node + 1,node + m + 1,cmp);
top = n;
for(int i = 1; i <= m; i ++){
int x = node[i].x,y = node[i].y;
int fx = Find(x),fy = Find(y);
if(fx == fy) continue;
w[++ top] = node[i].w;
add(top,fx); //add(fx,top);
add(top,fy); //add(fy,top);
far[fx] = top;
far[fy] = top;
if(top == 2 * n - 1) break;
}
for (int i = 1; i < N; ++i)
lg[i] = lg[i - 1] + (1 << lg[i - 1] == i);
t = (int)(log(top) / log(2)) + 1;
dfs(top, 0);
dfs1(top,1);
Build_Tree(root[0],1,len);
// printf("tot1 = %d\n",tot1);
for(int i = 1; i <= n; i ++){
// printf("h = %d\n",h[i]);
Update(root[i - 1],root[i],1,len,h[i]);
}
// printf("tot1 = %d\n",tot1);
b[0] = -1;
while(q --){
int u = read(),x = read(),k = read();
for(int i = 20; i >= 0; i --){
if(f[u][i] && w[f[u][i]] <= x) u = f[u][i];
}
if(w[u] == 0){
if(k == 1) printf("%d\n",high[u]);
else printf("-1\n"); continue;
}
// printf("u = %d\n",u);
// printf("l = %d r = %d root[l] = %d root[r] = %d\n",son[u][0],son[u][1],root[son[u][0]],root[son[u][1]]);
if(son[u][1] - son[u][0] < k) printf("-1\n");
else{
int s = query(root[son[u][0]],root[son[u][1]],1,len,k);
printf("%d\n",b[s]);
}
}
}
/*
3
1 2 3
2
2 6
*/
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