The diameter of the week tree of hiho11

 

Find any point as the root, then find the farthest point from this root, and then use this point as the root, and then find the farthest point from this root. The two distance and are the diameter of the tree.

#include<iostream>#include<cstdio>#include<cstring>#include<map>#include<vector>#include<stdlib.h>using namespace std;typedef long long LL;#define lson l,mid,rt<<1#define rson mid+1,r,rt<<1|1const int maxn = 1000000 + 1000;int sum[maxn << 2];const int INF = 1<<30;int ncnt;int val[maxn];int pos[maxn];void up(int rt){    sum[rt] = min(sum[rt << 1], sum[rt << 1 | 1]);}void build(int l, int r, int rt){    sum[rt] = INF;    if (l == r){        return;    }    int mid = (l + r) >> 1;    build(lson);    build(rson);    up(rt);}void update(int key, int l, int r, int rt){    if (l == r){        sum[rt] = key; return;    }    int mid = (l + r) >> 1;    if (key <= mid) update(key, lson);    else update(key, rson);    up(rt);}int ask(int L, int R, int l, int r, int rt){    if (L <= l&&r <= R) return sum[rt];    int ans = INF;    int mid = (l + r) >> 1;    if (L <= mid) ans = min(ans, ask(L, R, lson));    if (R > mid) ans = min(ans, ask(L, R, rson));    return ans;}void gao(int x){    int Min = INF; int ans=INF;    for (int i = ncnt - 1; i >= 1; i--){        if (val[i] % x == 0) {            printf("%d\n", i); return ;        }        if (val[i] % x < Min){            Min = val[i] % x;            ans = i;        }    }    printf("%d\n", ans);}void gao1(int x){    int l = 0; int r = x - 1; int ans = -1;    while (l <= maxn){        if (r > maxn) r = maxn;        int temp = ask(l, r, 0, maxn, 1);        if(temp!=INF){        if (ans==-1||temp%x < ans%x) ans = temp;        else if (temp%x == ans%x&&pos[temp]>pos[ans])            ans = temp;        }        l += x; r += x;    }    printf("%d\n", pos[ans]);}int main(){    char str[100];    int k;    int cnt = 0;    int T;    while (scanf("%d",&T),T){        if(cnt) puts("");        ncnt = 1;        build(0, maxn, 1);        printf("Case %d:\n", ++cnt);        while (T--){            scanf("%s%d", str, &k);            if (str[0] == ‘B‘){                val[ncnt] = k;                pos[k] = ncnt++;                update(k, 0, maxn, 1);            }            else{                if(ncnt==1){                    printf("-1\n");                }                else                if (k < 10000) gao(k);                else gao1(k);            }        }    }    return 0;}

 

The diameter of the week tree of hiho11