Color the ball

Posted 2020-10-27 啦啦啦

题解：终于会区间更新了！！

延迟标记：为了避免直接更新到叶节点，所以对  对应区间的结点  添加一个标记，记录本次更新的信息，不过当更新该结点的子结点时，一定要将

标记传递下去。这也是为什么在查询的时候也要传递标记。

 1 #pragma warning(disable:4996)
 2 #include <iostream>
 3 #include <cmath>
 4 #include <cstdio>
 5 #include <cstring>
 6 #include <algorithm>
 7 #define lson (root<<1)
 8 #define rson (root<<1|1)
 9 using namespace std;
10 
11 const int maxn = 1e5 + 5;
12 
13 int n, time;
14 
15 struct node {
16     int l;
17     int r;
18     int add;
19     int sum;
20 }Tree[maxn<<2];
21 
22 inline void Pushup(int root) {
23     Tree[root].sum = Tree[lson].sum + Tree[rson].sum;
24 }
25 
26 inline void Pushdown(int root) {
27     Tree[lson].add += Tree[root].add;
28     Tree[rson].add += Tree[root].add;
29     Tree[lson].sum += Tree[root].add*(Tree[lson].r - Tree[root].l + 1);
30     Tree[rson].sum += Tree[root].add*(Tree[rson].r - Tree[rson].l + 1);
31     Tree[root].add = 0;
32 }
33 
34 void Build(int l, int r, int root) {
35     Tree[root].l = l;
36     Tree[root].r = r;
37     Tree[root].add = 0;
38     if (l == r) { Tree[root].sum = 0; return; }
39     int mid = (l + r) >> 1;
40     Build(l, mid, lson);
41     Build(mid + 1, r, rson);
42     Pushup(root);
43 }
44 
45 void Update(int l, int r, int root) {
46     if (l >  Tree[root].r || r <  Tree[root].l) return;
47     if (l <= Tree[root].l && r >= Tree[root].r) {
48         Tree[root].add += 1;
49         Tree[root].sum += Tree[root].r - Tree[root].l + 1;   //~~~~~~~~~~~~~~~一定要在更新标记的时候顺便更新当前结点的sum
50         return;
51     }
52     if (Tree[root].add) Pushdown(root);
53     int mid = (l + r) >> 1;
54     Update(l, r, lson);
55     Update(l, r, rson);
56     Pushup(root);
57 }
58 
59 void Query(int root) {
60     if (Tree[root].l == Tree[root].r) {
61         time++;
62         printf("%d", Tree[root].sum);
63         if (time != n) printf(" ");
64         else printf("\\n");
65         return;
66     }
67     if (Tree[root].add) Pushdown(root);
68     Query(lson);
69     Query(rson);
70 }
71 
72 int main()
73 {
74     while (scanf("%d", &n) != EOF && n) {
75         Build(1, n, 1);
76         time = 0;
77         for (int i = 0; i < n; i++) {
78             int a, b;
79             scanf("%d%d", &a, &b);
80             Update(a, b, 1);
81         }
82         Query(1);
83     }
84     return 0;
85 }