hdu1556 Color the ball

思路:

线段树区间更新模板。

实现:

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 const int N = 100005;
 4 int tree[N * 4], lazy[N * 4], a[N];
 5 int n;
 6 
 7 void build()
 8 {
 9     memset(tree, 0, sizeof tree);
10     memset(lazy, 0, sizeof lazy);
11 }
12 
13 void pushdown(int num, int cl, int cr)
14 {
15     if (!lazy[num]) return;
16     tree[num * 2] += lazy[num] * cl;
17     tree[num * 2 + 1] += lazy[num] * cr;
18     lazy[num * 2] += lazy[num];
19     lazy[num * 2 + 1] += lazy[num];
20     lazy[num] = 0;
21 }
22 
23 void update(int num, int l, int r, int x, int y, int dx)
24 {
25     if (x <= l && y >= r) { tree[num] += (r - l + 1) * dx; lazy[num] += dx; return; }
26     int m = l + r >> 1;
27     pushdown(num, m - l + 1, r - m);
28     if (x <= m) update(num * 2, l, m, x, y, dx);
29     if (y >= m + 1) update(num * 2 + 1, m + 1, r, x, y, dx);
30     tree[num] = tree[num * 2] + tree[num * 2 + 1];
31 }
32 
33 int query(int num, int l, int r, int x, int y)
34 {
35     if (x <= l && y >= r) return tree[num];
36     int m = l + r >> 1;
37     pushdown(num, m - l + 1, r - m);
38     int ans = 0;
39     if (x <= m) ans += query(num * 2, l, m, x, y);
40     if (y >= m + 1) ans += query(num * 2 + 1, m + 1, r, x, y);
41     return ans;
42 }
43 
44 int main()
45 {
46     ios::sync_with_stdio(false);
47     while (cin >> n, n)
48     {
49         build();
50         int a, b;
51         for (int i = 0; i < n; i++) { cin >> a >> b; update(1, 1, n, a, b, 1); }
52         for (int i = 1; i <= n; i++) 
53         {    
54             cout << query(1, 1, n, i, i);
55             if (i != n) cout << " ";
56         }
57         cout << endl;
58     }
59     return 0;
60 }
原文地址:https://www.cnblogs.com/wangyiming/p/8446835.html