hdu2795

题意：有一个h*w的木板，放置一些1*L的物品，将物品尽可能的往上面和左边放置。

思路：维护一个区间的可以容纳板子长度的最大值

AC代码：

 1 #include <cstdio>
 2 #include <iostream>
 3 #include <cstring>
 4 #include <cmath>
 5 #include <algorithm>
 6 #include <cstdlib>
 7
 8 using namespace std;
 9
10 const int maxn = 200000 + 10;
11
12 int h, w, n, x;
13
14 struct node
15 {
16     int l, r, v;
17
18 } b[maxn<<2];
19
20 void build(int l, int r, int i)
21 {
22     b[i].l = l;
23     b[i].r = r;
24     int m = (l + r) >> 1;
25     if(l == r) {
26         b[i].v = w;
27         return ;
28     }
29     build(l, m, i<<1);
30     build(m+1, r, i<<1|1);
31     b[i].v = max(b[i<<1].v, b[i<<1|1].v);
32 }
33
34 int Query(int id, int num, int i)
35 {
36     int ret;
37     if(b[i].l == b[i].r) {
38         b[i].v -= num;
39         return b[i].l;
40     }
41     else {
42         if(num <= b[i<<1].v) ret = Query(id, num, i<<1);
43         else ret = Query(id, num, i<<1|1);
44     }
45     b[i].v = max(b[i<<1].v, b[i<<1|1].v);
46     return ret;
47 }
48
49 int main()
50 {
51     //freopen("test.in", "r", stdin);
52     while(scanf("%d%d%d", &h, &w, &n) != EOF) {
53         int H = min(h, n);
54         build(1, H, 1);
55         for(int i = 1; i <= n; i++) {
56             scanf("%d", &x);
57             if(b[1].v < x) puts("-1");
58             else printf("%d\n", Query(1, x, 1));
59         }
60     }
61     return 0;
62 }