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@liudongmiao
Last active August 29, 2015 13:57
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import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
public class MinDepth {
private static void mindepth(int[] array, int index, int depth, HashMap<Integer, int[]> maps) {
List<Integer> added = new ArrayList<Integer>();
for (int i = 0; i < index; ++i) {
if (array[i] + i >= index) {
int olddepth;
if (maps.containsKey(i)) {
olddepth = maps.get(i)[0];
} else {
olddepth = Integer.MAX_VALUE;
}
if (depth < olddepth) {
if (!maps.containsKey(i)) {
added.add(i);
}
maps.put(i, new int[] { depth, index });
}
}
}
for (int key : added) {
mindepth(array, key, maps.get(key)[0] + 1, maps);
}
}
public static void mindepth(int[] array) {
int length = array.length;
HashMap<Integer, int[]> maps = new HashMap<Integer, int[]>();
maps.put(length - 1, new int[] { 0, length });
mindepth(array, length - 1, 1, maps);
System.out.println("input: " + Arrays.toString(array));
if (maps.containsKey(0)) {
System.out.println("count: " + maps.get(0)[0]);
int i = 0;
while (maps.containsKey(i) && i < length) {
System.out.println("steps: " + array[i] + ", index: " + i);
i = maps.get(i)[1];
}
} else {
System.out.println("count: -1");
}
}
public static void main(String... args) {
ArrayList<Integer> list = new ArrayList<Integer>();
for (String arg : args) {
for (String i : arg.split(",")) {
try {
list.add(Integer.parseInt(i.trim()));
} catch (NumberFormatException e) {
// do nothing
}
}
}
int[] array = new int[list.size()];
for (int i = 0; i < list.size(); ++i) {
array[i] = list.get(i);
}
mindepth(array);
}
}
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