hdu 6430 線段樹 暴力維護
阿新 • • 發佈:2018-08-23
mission ini common enc deep edge tree def acc
As we know, TeaTree is a tree and her root is node 1, she have n nodes and n-1 edge, for each node i, it has it’s value v[i].
For every two nodes i and j (i is not equal to j), they will tell their Lowest Common Ancestors (LCA) a number : gcd(v[i],v[j]).
For each node, you have to calculate the max number that it heard. some definition:
In graph theory and computer science, the lowest common ancestor (LCA) of two nodes u and v in a tree is the lowest (deepest) node that has both u and v as descendants, where we define each node to be a descendant of itself.
Input
On the first line, there is a positive integer n, which describe the number of nodes.
Next line there are n-1 positive integers f[2] ,f[3], …, f[n], f[i] describe the father of node i on tree.
Next line there are n positive integers v[2] ,v[3], …, v[n], v[i] describe the value of node i.
n<=100000, f[i]<i, v[i]<=100000
For the nodes who heard nothing, output -1. 求樹上每點的一個值 這個值 是 該點 以及它的子樹所有點的 最大gcd
Problem E. TeaTree
Time Limit: 8000/4000 MS (Java/Others) Memory Limit: 524288/524288 K (Java/Others)
Total Submission(s): 722 Accepted Submission(s): 255
As we know, TeaTree is a tree and her root is node 1, she have n nodes and n-1 edge, for each node i, it has it’s value v[i].
For each node, you have to calculate the max number that it heard. some definition:
In graph theory and computer science, the lowest common ancestor (LCA) of two nodes u and v in a tree is the lowest (deepest) node that has both u and v as descendants, where we define each node to be a descendant of itself.
Next line there are n-1 positive integers f[2] ,f[3], …, f[n], f[i] describe the father of node i on tree.
Next line there are n positive integers v[2] ,v[3], …, v[n], v[i] describe the value of node i.
Output Your output should include n lines, for i-th line, output the max number that node i heard.
For the nodes who heard nothing, output -1. 求樹上每點的一個值 這個值 是 該點 以及它的子樹所有點的 最大gcd
#include <iostream> #include <vector> #define rep(i,a,b) for(int i=a;i<b;i++) #define per(i,a,b) for(int i=a-1;i>=b;i--) const int MX = 1e5; const int MXX = 400*MX; using namespace std; int n; vector<int> G[MX+5],vv[MX+5]; // init函數 實現將i因數分解 (i < 1e5) void init() { rep(i,1,MX+1) vv[i].push_back(1); rep(i,2,MX+1) { vv[i].push_back(i); for(int j=i+i;j<=MX;j+=i) vv[j].push_back(i); } // rep(i,1,MX+1) { // rep(j,0,vv[i].size()) { // printf("%d ",vv[i][j]); // }puts(""); // } } int root[MX+5],ls[MXX],rs[MXX],sum[MXX],rear,ans[MX]; inline void push_up(int rt) { if(ls[rt] && rs[rt]) sum[rt] = max(sum[ls[rt]],sum[rs[rt]]); else if(ls[rt]) sum[rt] = sum[ls[rt]]; else if(rs[rt]) sum[rt] = sum[rs[rt]]; } void update(int &rt,int l,int r,int p) { if(rt==0) rt = ++rear; if(l == r) { sum[rt] = p; return ; } int m = (l+r)>>1; if(p <= m) update(ls[rt],l,m,p); else update(rs[rt],m+1,r,p); push_up(rt); } int merge(int rt, int prt, int &ans) { if(rt==0 || prt==0) return rt^prt; //這裏維護最大的gcd if(sum[rt] == sum[prt]) ans = max(ans,sum[rt]); //這裏只有有因子,就歸並到rt上面 if(ls[rt] | ls[prt]) ls[rt] = merge(ls[rt], ls[prt], ans); if(rs[rt] | rs[prt]) rs[rt] = merge(rs[rt], rs[prt], ans); push_up(rt); return rt; } void dfs(int u) { ans[u] = -1; rep(i, 0, G[u].size()) { int v = G[u][i]; dfs(v); root[u] = merge(root[u],root[v],ans[u]); } } int main () { freopen("in.txt" ,"r",stdin); freopen("out.txt","w",stdout); init(); scanf("%d", &n); //建邊 rep(i,2,n+1) { int fa; scanf("%d",&fa); G[fa].push_back(i); } //對每個v[i]建線段樹 rear=0; rep(i,1,n+1) { int x; scanf("%d", &x); root[i]=0; rep(j, 0, vv[x].size()) { update(root[i], 1, MX, vv[x][j]); } } //暴力更新 gcd dfs(1); //輸出答案 rep(i,1,n+1) printf("%d\n", ans[i]); return 0; }
hdu 6430 線段樹 暴力維護