http://acm.hdu.edu.cn/showproblem.php?pid=4010?(題目鏈接)

題意

　　link cut tree板子

Solution

　　link cut tree

細節

　　注意第二個詢問切的是什么

代碼

// hdu4010 #include<algorithm> #include<iostream> #include<cstdlib> #include<cstring> #include<cstdio> #include<vector> #include<cmath> #define LL long long #define inf 2147483647 #define Pi acos(-1.0) #define free(a) freopen(a".in","r",stdin),freopen(a".out","w",stdout); using namespace std;const int maxn=300010; int val[maxn],tag[maxn],rev[maxn],fa[maxn],mx[maxn],tr[maxn][2]; int n,m;void Init() {memset(tag,0,sizeof(tag));memset(fa,0,sizeof(fa));memset(rev,0,sizeof(rev));memset(tr,0,sizeof(tr));mx[0]=-inf; } void pushup(int x) {mx[x]=max(mx[tr[x][0]],mx[tr[x][1]]);mx[x]=max(mx[x],val[x]); } void pushdown(int x) {int l=tr[x][0],r=tr[x][1];if (tr[fa[x]][0]==x || tr[fa[x]][1]==x) pushdown(fa[x]);if (rev[x]) {swap(tr[x][0],tr[x][1]);rev[l]^=1;rev[r]^=1;rev[x]^=1;}if (tag[x]) {if (l) tag[l]+=tag[x],mx[l]+=tag[x],val[l]+=tag[x];if (r) tag[r]+=tag[x],mx[r]+=tag[x],val[r]+=tag[x];tag[x]=0;} } void rotate(int x) {int y=fa[x],z=fa[y],l,r;if (tr[y][0]==x) l=0;else l=1;r=l^1;if (tr[fa[y]][0]==y || tr[fa[y]][1]==y) tr[z][tr[z][1]==y]=x;fa[x]=z;fa[y]=x;fa[tr[x][r]]=y;tr[y][l]=tr[x][r];tr[x][r]=y;pushup(y);pushup(x); } void splay(int x) {pushdown(x);while (tr[fa[x]][0]==x || tr[fa[x]][1]==x) {int y=fa[x],z=fa[y];if (tr[z][0]==y || tr[z][1]==y) {if (tr[y][0]==x ^ tr[z][0]==y) rotate(x);else rotate(y);}rotate(x);} } int find(int x) {while (fa[x]) x=fa[x];return x; } void access(int x) {for (int y=0;x;y=x,x=fa[x])splay(x),tr[x][1]=y,pushup(x); } void makeroot(int x) {access(x);splay(x);rev[x]^=1; } void link(int x,int y) {makeroot(x);fa[x]=y; } void cut(int x,int y) {makeroot(x);access(y);splay(y);tr[y][0]=fa[tr[y][0]]=0;//注意這個地方，要求斷的是y和其祖先的邊pushup(y); } void modify(int x,int y,int w) {makeroot(x);access(y);splay(y);tag[y]+=w;mx[y]+=w;val[y]+=w; } int query(int x,int y) {makeroot(x);access(y);splay(y);return mx[y]; } int main() {while (scanf("%d",&n)!=EOF) {Init();for (int u,v,i=1;i<n;i++) {scanf("%d%d",&u,&v);link(u,v);}for (int i=1;i<=n;i++) scanf("%d",&val[i]),mx[i]=val[i];scanf("%d",&m);for (int op,x,y,w,i=1;i<=m;i++) {scanf("%d",&op);if (op==1) {scanf("%d%d",&x,&y);if (find(x)==find(y)) {puts("-1");continue;}link(x,y);}if (op==2) {scanf("%d%d",&x,&y);if (x==y || find(x)!=find(y)) {puts("-1");continue;}cut(x,y);}if (op==3) {scanf("%d%d%d",&w,&x,&y);if (find(x)!=find(y)) {puts("-1");continue;}modify(x,y,w);}if (op==4) {scanf("%d%d",&x,&y);if (find(x)!=find(y)) {puts("-1");continue;}printf("%d\n",query(x,y));}}puts("");}return 0; }

?

轉載于:https://www.cnblogs.com/MashiroSky/p/6376580.html

總結

以上是生活随笔為你收集整理的【hdu4010】 Query on The Trees的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。