月饼

题解：线段树，区间更新，单点查询！还是不太明白延迟标记是怎么用的！！！！
 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, m, ans;
14 
15 struct node {
16     int l, r, sum, add;
17 }Tree[maxn<<2];
18 
19 inline void Pushup(int root) { Tree[root].sum = Tree[lson].sum + Tree[rson].sum; }
20 
21 inline void Pushdown(int root) {
22     Tree[lson].add += Tree[root].add;
23     Tree[rson].add += Tree[root].add;
24     Tree[lson].sum += Tree[root].add*(Tree[lson].r - Tree[lson].l + 1);
25     Tree[rson].sum += Tree[root].add*(Tree[rson].r - Tree[rson].l + 1);
26     Tree[root].add = 0;
27 }
28 
29 void Build(int l, int r, int root) {
30     Tree[root].l = l;
31     Tree[root].r = r;
32     Tree[root].add = 0;
33     if (l == r) {
34         Tree[root].sum = 100;
35         return;
36     }
37     int mid = (l + r) >> 1;
38     Build(l, mid, lson);
39     Build(mid + 1, r, rson);
40     Pushup(root);
41 }
42 
43 void Update(int l, int r, int root, int x) {
44     if (r <  Tree[root].l || l >  Tree[root].r) return;
45     if (l <= Tree[root].l && r >= Tree[root].r) {
46         Tree[root].add += x;
47         Tree[root].sum += x * (Tree[root].r - Tree[root].l + 1);
48         return;
49     }
50     if (Tree[root].add) Pushdown(root);
51     Update(l, r, lson, x);
52     Update(l, r, rson, x);
53     Pushup(root);
54 }
55 
56 void Query(int root, int x) {
57     
58     if (Tree[root].l == Tree[root].r) {
59         if (Tree[root].l == x) ans = Tree[root].sum;
60         return;
61     }
62     if (Tree[root].add) Pushdown(root);
63     int mid = (Tree[root].l + Tree[root].r) >> 1;
64     if (x <= mid) Query(lson, x);
65     else Query(rson, x);
66 }
67 
68 int main()
69 {    
70     while (scanf("%d%d", &n, &m) != EOF) {
71         Build(1, n, 1);
72         for (int i = 0; i < m; i++) {
73             char op[2];
74             scanf("%s", op);
75             if (op[0] == 'L') {
76                 int a, b, c;
77                 scanf("%d%d%d", &a, &b, &c);
78                 Update(a, b, 1, c);
79             }
80             else {
81                 int a;
82                 scanf("%d", &a);
83                 Query(1, a);
84                 printf("%d
", ans);
85             }
86         }
87     }
88     return 0;
89 }