2012-06-03 19:18:30Morris
[UVA][ST] 12299 - RMQ with Shifts
RMQ with Shifts
RMQ with Shifts |
In the traditional RMQ (Range Minimum Query) problem, we have a static array A. Then for each query (L, R) (LR), we report the minimum value among A[L], A[L + 1], ..., A[R]. Note that the indices start from 1, i.e. the left-most element is A[1].
In this problem, the array A is no longer static: we need to support another operation
shift(i1, i2, i3,..., ik)(i1 < i2 < ... < ik, k > 1)
we do a left ``circular shift" of A[i1], A[i2], ..., A[ik].
For example, if A={6, 2, 4, 8, 5, 1, 4}, then shift(2, 4, 5, 7) yields {6, 8, 4, 5, 4, 1, 2}. After that, shift(1, 2) yields 8, 6, 4, 5, 4, 1, 2.
Input
There will be only one test case, beginning with two integers n, q ( 1n100, 000, 1q250, 000), the number of integers in array A, and the number of operations. The next line contains n positive integers not greater than 100,000, the initial elements in array A. Each of the next q lines contains an operation. Each operation is formatted as a string having no more than 30 characters, with no space characters inside. All operations are guaranteed to be valid.
Warning: The dataset is large, better to use faster I/O methods.
Output
For each query, print the minimum value (rather than index) in the requested range.
Sample Input
7 5 6 2 4 8 5 1 4 query(3,7) shift(2,4,5,7) query(1,4) shift(1,2) query(2,2)
Sample Output
1 4 6
#include <stdio.h>
#include <string.h>
#define min(x, y) ((x) < (y) ? (x) : (y))
int tree[524289], M;
int A[262145];
void setTree() {
int i;
for(i = 2*M-1; i > 0; i--) {
if(i >= M) {
tree[i] = A[i-M];
} else {
tree[i] = min(tree[i<<1], tree[i<<1|1]);
}
}
}
int query(int s, int t) {
static int i, ans;
ans = 0xfffffff;
for(s = s+M-1, t = t+M+1; (s^t) != 1; ) {
if(~s&1) {
ans = min(ans, tree[s^1]);
}
if(t&1) {
ans = min(ans, tree[t^1]);
}
s >>= 1, t >>= 1;
}
return ans;
}
void clear(int s) {
while(s > 0) {
tree[s] = 0xfffffff;
s >>= 1;
}
}
void update(int s) {
while(s > 0) {
tree[s] = min(tree[s<<1], tree[s<<1|1]);
s >>= 1;
}
}
int main() {
int n, m, i, j;
char cmd[1000];
while(scanf("%d %d", &n, &m) == 2) {
for(M = 1; M < n+2; M <<= 1);
memset(A, 63, sizeof(A));
for(i = 1; i <= n; i++)
scanf("%d", &A[i]);
setTree();
getchar();
int a[50], tmp, g, idx;
while(m--) {
gets(cmd);
if(cmd[0] == 'q') {
sscanf(cmd+6, "%d,%d", &i, &j);
printf("%d\n", query(i, j));
} else {
tmp = 0, g = 0, idx = 0;
for(i = 6; cmd[i]; i++) {
if(cmd[i] >= '0' && cmd[i] <= '9')
tmp = tmp*10 + cmd[i]-'0', g = 1;
else {
if(g) {
a[idx++] = tmp;
clear(tmp+M);
}
tmp = 0, g = 0;
}
}
tmp = A[a[0]];
for(i = 1; i < idx; i++) {
A[a[i-1]] = A[a[i]];
}
A[a[idx-1]] = tmp;
for(i = 0; i < idx; i++) {
tree[a[i]+M] = A[a[i]];
update((a[i]+M)>>1);
}
}
}
}
return 0;
}