hihoCoder#1068 RMQ-ST算法

 1 #include <iostream>
 2 #include <cstring>
 3 #include <cmath>
 4 
 5 using namespace std;
 6 
 7 #define MAX_SIZE 1000010
 8 
 9 int N, Q;
10 int w[MAX_SIZE];
11 int q[MAX_SIZE][32];
12 
13 void build() {
14   for (int i = 1; (1 << i) <= N; i++) {
15     for (int j = 0; j + (1 << i) <= N; j++) {
16       q[j][i] = min(q[j][i - 1], q[j + (1 << (i - 1))][i - 1]);
17     }
18   }
19 }
20 
21 int query(int l, int r) {
22   int len = r - l + 1;
23   int i = 0;
24 
25   while ((1 << (i + 1)) <= len)
26     i++;
27   return min(q[l][i], q[r - (1 << i) + 1][i]);
28 }
29 
30 int main() {
31   scanf("%d", &N);
32   for (int i = 0; i < N; i++) {
33     scanf("%d", &(w[i]));
34     q[i][0] = w[i];
35   }
36 
37   build();
38 
39   scanf("%d", &Q);
40   while (Q--) {
41     int l, r;
42     scanf("%d%d", &l, &r);
43     printf("%d\n", query(l - 1, r - 1));
44   }
45 
46   return 0;