[BZOJ 2716]天使玩偶

K-D Tree模板


#include 
#include 
#include 
#include 
#include 
#define maxn 500010
using namespace std;int n, m, D;void read(int &num){num = 0;char ch = getchar();int flag = 1;for(; ch < '!'; ch = getchar());if(ch == '-')flag = -1;for(; ch > '!'; ch = getchar())num = num * 10 + ch - 48;num = num * flag;
}struct Point{#define N 2int d[N], mn[N], mx[N], l, r;int& operator[](int i){return d[i];}bool operator<(Point p)const{return d[D] < p[D];}Point(int x = 0, int y = 0){d[0] = x;d[1] = y;l = 0, r = 0;for(int i = 0; i < 2; i ++)mn[i] = mx[i] = 0;}
}p[maxn];const int inf = 0x7fffffff;
int Abs(int x){return x > 0 ? x : -x;
}int dis(Point a, Point b){return Abs(a[0] - b[0]) + Abs(a[1] - b[1]);
}
namespace K_Dtree{int root, ans;Point P, t[maxn << 1];#define L(p) t[p].l#define R(p) t[p].rvoid update(int p){for(int i = 0; i < 2; i ++){t[p].mn[i] = t[p].mx[i] = t[p].d[i];if(L(p)){t[p].mn[i] = min(t[p].mn[i], t[L(p)].mn[i]);t[p].mx[i] = max(t[p].mx[i], t[L(p)].mx[i]);}if(R(p)){t[p].mn[i] = min(t[p].mn[i], t[R(p)].mn[i]);t[p].mx[i] = max(t[p].mx[i], t[R(p)].mx[i]);}}}int build(int l, int r, int now){int mid = l + r >> 1;D = now;nth_element(p + l, p + mid, p + r + 1);t[mid] = p[mid];if(l < mid)L(mid) = build(l, mid - 1, now ^ 1);if(r > mid)R(mid) = build(mid + 1, r, now ^ 1);update(mid);return mid;}void insert(int p, int now){if(P[now] >= t[p][now]){if(R(p))insert(R(p), now ^ 1);else{t[p].r = ++ n;t[n] = P;update(n);}}else{if(L(p))insert(L(p), now ^ 1);else{t[p].l = ++ n;t[n] = P;update(n);}}update(p);}int dist(int p1, Point p){int ans = 0;for(int i = 0; i < 2; i ++)ans += max(0, t[p1].mn[i] - p[i]);	for(int i = 0; i < 2; i ++)	    ans += max(0, p[i] - t[p1].mx[i]);return ans;}void ask(int p, int now){int dl = inf, dr = inf;ans = min(ans, dis(t[p], P));if(L(p))dl = dist(L(p), P);if(R(p))dr = dist(R(p), P);if(dl < dr){if(L(p) && dl < ans)ask(L(p), now ^ 1);if(R(p) && dr < ans)ask(R(p), now ^ 1);}else{if(R(p) && dr < ans)ask(R(p), now ^ 1);if(L(p) && dl < ans)ask(L(p), now ^ 1);}}void insert(const Point& __){P = __;insert(root, 0);}void init(){root = build(1, n, 0);}int ask(const Point& __){P = __;ans = inf;ask(root, 0);return ans;}
}int main(){read(n), read(m);for(int i = 1; i <= n; i ++)read(p[i][0]), read(p[i][1]);K_Dtree::init();int opt, x, y;while(m --){read(opt), read(x), read(y);if(opt == 1)K_Dtree::insert(Point(x, y));elseprintf("%d\n", K_Dtree::ask(Point(x, y)));}return 0;
}

[3.28 upd]又复习了一遍,发现insert和ask不会写了

最重要的是nth_element(t+l,t+mid,t+1+r)写成1~n了!

稀里哇啦wa一片


#include 
#define maxn 1000010
using namespace std;int n, m, D;struct Node{int d[2], mn[2], mx[2], l, r;Node(int x = 0, int y = 0){d[0] = x, d[1] = y;mn[0] = mn[1] = mx[0] = mx[1] = l = r = 0;}int& operator[](const int& k){return d[k];}bool operator<(Node k)const{return d[D] < k[D];}
}t[maxn], T;int root;void update(int id){for(int i = 0; i < 2; i ++){t[id].mn[i] = t[id].mx[i] = t[id][i];if(t[id].l){t[id].mn[i] = min(t[id].mn[i], t[t[id].l].mn[i]);t[id].mx[i] = max(t[id].mx[i], t[t[id].l].mx[i]);}if(t[id].r){t[id].mn[i] = min(t[id].mn[i], t[t[id].r].mn[i]);t[id].mx[i] = max(t[id].mx[i], t[t[id].r].mx[i]);}}
}int build(int l, int r, int type){if(l > r)return 0;D = type; int mid = l + r >> 1;nth_element(t+l, t+mid, t+1+r);t[mid].l = build(l, mid-1, type^1);t[mid].r = build(mid+1, r, type^1);update(mid);return mid;
}int dist(int id){int ret = 0;for(int i = 0; i < 2; i ++){ret += max(0, t[id].mn[i] - T[i]);ret += max(0, T[i] - t[id].mx[i]);}return ret;
}inline int Abs(int x){return x > 0 ? x : -x;}inline int ask_dis(Node a, Node b){return Abs(a[0] - b[0]) + Abs(a[1] - b[1]);}void insert(int id, int type){if(T[type] >= t[id][type]){if(t[id].r)insert(t[id].r, type^1);else{t[id].r = ++ n;t[n] = T;update(n);}}else{if(t[id].l)insert(t[id].l, type^1);else{t[id].l = ++ n;t[n] = T;update(n);}}update(id);
}void Insert(Node P){T = P;insert(root, 0);
}int ans;
const int inf = 0x7fffffff;void ask(int id, int type){int dl = inf, dr = inf;ans = min(ans, ask_dis(t[id], T));if(t[id].l)dl = dist(t[id].l);if(t[id].r)dr = dist(t[id].r);if(dl < dr){if(t[id].l && dl < ans)ask(t[id].l, type^1);if(t[id].r && dr < ans)ask(t[id].r, type^1);}else{if(t[id].r && dr < ans)ask(t[id].r, type^1);if(t[id].l && dl < ans)ask(t[id].l, type^1);}
}int ask(Node P){T = P;ans = inf;ask(root, 0);return ans;
}int main(){scanf("%d%d", &n, &m);for(int i = 1; i <= n; i ++)scanf("%d%d", &t[i][0], &t[i][1]);root = build(1, n, 0);int opt, x, y;while(m --){scanf("%d%d%d", &opt, &x, &y);if(opt == 1)Insert(Node(x, y));else printf("%d\n", ask(Node(x, y)));}return 0;
}



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