暑假集训－－线段树

 1 struct SegmentTree
 2 {
 3     int l, r;
 4     int data;
 5 } t[N * 4 + 5];
 6 int a[N];  //原始数据数组
 7 void build(int p,int l,int r)  //存储区间和的线段树
 8 {
 9     t[p].l = l, t[p].r = r;  //节点p代表[l,r]
10     if(l==r) //单点
11     {
12         t[p].data = a[l]; 
13         return;
14     }
15     int m = (l + r) / 2;  //折半
16     int ls = 2 * p, rs = ls + 1;
17     build(ls, l, m);      //建左子树
18     build(rs, m + 1, r);  //建右子树
19     t[p].data = t[ls].data + t[rs].data;   //p代表的区间和 = ls代表的区间和 + rs代表的区间和
20 }

 1 void build(int p,int l,int r)  //存储区间最大值的线段树
 2 {
 3     t[p].l = l, t[p].r = r;
 4     if(l==r) 
 5     {
 6         t[p].date = a[l];
 7         return;
 8     }
 9     int m = (l + r) / 2;
10     int ls = 2 * p, rs = ls + 1;
11     build(ls, l, m);
12     build(rs, m + 1, r);
13     t[p].date = max(t[ls].date,t[rs].date);  //p区间的最大值 = max(ls最大值,rs最大值)
14 }

 1 void add(int p,int x,int v)  //将x位置的数增加v  同样是存储区间和的线段树
 2 {
 3     if(t[p].l==t[p].r)
 4     {
 5         t[p].data += v;
 6         return;
 7     }
 8     int m = (t[p].l + t[p].r) / 2;
 9     int ls = 2 * p, rs = ls + 1;
10     if(x<=m)
11         add(ls, x, v);
12     else
13         add(rs, x, v);
14     t[p].data = t[ls].data + t[rs].data;
15 }

 1 void add(int p,int x,int v)  //维护区间最大值的线段树  将x位置的数值改为v
 2 {
 3     if(t[p].l==t[p].r)
 4     {
 5         t[p].date = v;
 6         return;
 7     }
 8     int m = (t[p].l + t[p].r) / 2;
 9     int ls = 2 * p, rs = ls + 1;
10     if(x<=m)
11         add(ls, x, v);
12     else
13         add(rs, x, v);
14     t[p].date = max(t[ls].date,t[rs].date);
15 }

 1 int Query(int p,int l,int r)  //询问l-r区间和
 2 {
 3     if(l<=t[p].l&&r>=t[p].r) //l-r完全覆盖了p代表的区间
 4     {
 5         return t[p].data;  //直接返回值
 6     }
 7     int m = (t[p].l + t[p].r) / 2;   //向下取整
 8     int ls = 2 * p, rs = ls + 1;
 9     int sum = 0;
10     if(l<=m)  //p此时的区间的左半边和l-r有交集但不完全被完全覆盖
11     {
12         sum += Query(ls, l, m); //查询左半边 此时的l-r其实是l-m
13     }
14     if(r>m)   //这里没有等于
15     {
16         sum += Query(rs, m + 1, r);  //同理
17     }
18 }

 1 int Query(int p,int l,int r)  //询问区间最大值
 2 {
 3     if(l<=t[p].l&&r>=t[p].r)
 4     {
 5         return t[p].date;
 6     }
 7     int m = (t[p].l + t[p].r) / 2;
 8     int ls = 2 * p, rs = ls + 1;
 9     int maxx=-inf;  //初始化最大值为-inf
10     if(l<=m)
11            maxx=max(maxx,Query(ls,l,r));
12     if(r>m)
13         maxx=max(maxx,Query(rs,l,r));
14     return maxx;
15 }

 1 struct SegmentTree
 2 {
 3     int l, r;
 4     ll sum, add;   //add为增量延迟标记
 5     #define l(x) t[x].l
 6     #define r(x) t[x].r
 7     #define sum(x) t[x].sum
 8     #define add(x) t[x].add
 9 } t[N * 4];
10 int a[N], n, m;
11 void build(int p,int l,int r)
12 {
13     l(p) = l, r(p) = r;
14     if(l==r)
15     {
16         sum(p) = a[l];
17         return;
18     }
19     int m = (l + r) / 2;
20     int ls = 2 * p, rs = 2 * p + 1;
21     build(ls, l, m);
22     build(rs, m + 1, r);
23     sum(p) = sum(ls) + sum(rs);
24 }
25 void spread(int p)
26 {
27     if(add(p))
28     {
29         int ls = 2 * p, rs = 2 * p + 1;
30         sum(ls) += add(p) * (r(ls) - l(ls) + 1);
31         sum(rs) += add(p) * (r(rs) - l(rs) + 1);
32         add(ls) += add(p);
33         add(rs) += add(p);
34         add(p) = 0;
35     }
36 }
37 void change(int p,int l,int r,int d)
38 {
39     if(l<=l(p)&&r>=r(p))
40     {
41         sum(p) += (ll)d * (r(p) - l(p) + 1);
42         add(p) += d;
43         return;
44     }
45     spread(p);
46     int m = (l(p) + r(p)) / 2;
47     int ls = 2 * p, rs = 2 * p + 1;
48     if(l<=m)
49         change(ls, l, r, d);
50     if(r>m)
51         change(rs, l, r, d);
52     sum(p) = sum(ls) + sum(rs);
53 }
54 ll ask(int p,int l,int r)
55 {
56     if(l<=l(p)&&r>=r(p))
57         return sum(p);
58     spread(p);
59     int m = (l(p) + r(p)) / 2;
60     int ls = 2 * p, rs = 2 * p + 1;
61     ll val = 0;
62     if(l<=m)
63         val += ask(ls, l, r);
64     if(r>m)
65         val += ask(rs, l, r);
66     return val;
67 }