九度oj 1544 数字序列区间最小值

原题链接：http://ac.jobdu.com/problem.php?pid=1544

RMQ线段树。。。

如下：

 1 #include<algorithm>
 2 #include<iostream>
 3 #include<cstdlib>
 4 #include<cstring>
 5 #include<cstdio>
 6 using std::min;
 7 const int Max_N = 101000;
 8 const int INF = 0x7fffffff;
 9 struct SegTree{
10     struct Node{
11         int v;
12     }seg[Max_N << 2];
13     void init(int n){
14         built(1, 1, n);
15     }
16     inline void built(int root, int l, int r){
17         if (l == r){
18             scanf("%d", &seg[root].v);
19             return;
20         }
21         int mid = (l + r) >> 1;
22         built(root << 1, l, mid);
23         built(root << 1 | 1, mid + 1, r);
24         seg[root].v = min(seg[root << 1].v, seg[root << 1 | 1].v);
25     }
26     inline int query(int root, int l, int r, int x, int y){
27         if (x > r || y < l) return INF;
28         if (x <= l && y >= r){
29             return seg[root].v;
30         }
31         int mid = (l + r) >> 1;
32         int v1 = query(root << 1, l, mid, x, y);
33         int v2 = query(root << 1 | 1, mid + 1, r, x, y);
34         return min(v1, v2);
35     }
36     inline void gogo(int n){
37         int m, a, b;
38         scanf("%d", &m);
39         while (m--){
40             scanf("%d %d", &a, &b);
41             printf("%d\n", query(1, 1, n, a, b));
42         }
43     }
44 }sg;
45 int main(){
46 #ifdef LOCAL
47     freopen("in.txt", "r", stdin);
48     freopen("out.txt", "w+", stdout);
49 #endif
50     int n;
51     while (~scanf("%d", &n)){
52         sg.init(n), sg.gogo(n);
53     }
54     return 0;
55 }
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posted @ 2015-05-04 21:43  GadyPu  阅读(185)  评论(0)  编辑  收藏  举报