g2601_2700.s2612_minimum_reverse_operations.Solution Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of leetcode-in-java21 Show documentation
Show all versions of leetcode-in-java21 Show documentation
Java-based LeetCode algorithm problem solutions, regularly updated
package g2601_2700.s2612_minimum_reverse_operations;
// #Hard #Array #Breadth_First_Search #Ordered_Set
// #2023_08_30_Time_19_ms_(100.00%)_Space_59_MB_(78.00%)
import java.util.ArrayList;
import java.util.List;
public class Solution {
public int[] minReverseOperations(int n, int p, int[] banned, int k) {
int[] out = new int[n];
for (int i = 0; i < n; i++) {
out[i] = -1;
}
for (int node : banned) {
out[node] = -2;
}
List nodes = new ArrayList<>();
nodes.add(p);
int depth = 0;
out[p] = depth;
int step = k - 1;
int[] nextNode2s = new int[n + 1];
for (int i = 0; i < n + 1; i++) {
nextNode2s[i] = i + 2;
}
while (!nodes.isEmpty()) {
depth++;
List newNodes = new ArrayList<>();
for (int node1 : nodes) {
int loReverseStart = Math.max(node1 - step, 0);
int hiReverseStart = Math.min(node1, n - k);
int loNode2 = 2 * loReverseStart + k - 1 - node1;
int hiNode2 = 2 * hiReverseStart + k - 1 - node1;
int postHiNode2 = hiNode2 + 2;
int node2 = loNode2;
while (node2 <= hiNode2) {
int nextNode2 = nextNode2s[node2];
nextNode2s[node2] = postHiNode2;
if (node2 < n && out[node2] == -1) {
newNodes.add(node2);
out[node2] = depth;
}
node2 = nextNode2;
}
}
nodes = newNodes;
}
for (int i = 0; i < n; i++) {
if (out[i] == -2) {
out[i] = -1;
}
}
return out;
}
}