hihoCoder#1068 RMQ-ST算法

原题地址

 

Spare Table练习

记得用scanf和printf输入输出，否则会TLE

 

代码：

 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;