88 lines
1.9 KiB
Java
88 lines
1.9 KiB
Java
package search;
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/**
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* @author Nikita Doschennikov (me@fymio.us)
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*/
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public class BinarySearch3637 {
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public static void main(String[] args) {
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IntList a = new IntList();
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int x = Integer.parseInt(args[0]);
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int n = args.length;
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for (int i = 1; i < n; i++) {
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a.put(Integer.parseInt(args[i]));
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}
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int start = searchIterativeDecreasing(x, a);
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int end = searchIterativeIncreasing(x, a.getReversed());
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System.out.println(((end - start) == -1) ? 0 : (end - start));
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}
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static int searchIterativeIncreasing(int x, IntList a) {
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if (a.getLength() == 0) {
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return 0;
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}
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int low = 0,
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high = a.getLength() - 1;
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while (low <= high) {
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int mid = low + (high - low) / 2;
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if (a.get(mid) <= x) {
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low = mid + 1;
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} else {
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high = mid - 1;
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}
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}
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return low;
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}
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static int searchIterativeDecreasing(int x, IntList a) {
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if (a.getLength() == 0) {
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return 0;
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}
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int low = 0,
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high = a.getLength() - 1;
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while (low <= high) {
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int mid = low + (high - low) / 2;
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if (a.get(mid) <= x) {
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high = mid - 1;
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} else {
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low = mid + 1;
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}
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}
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return low;
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}
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static int searchRecursive(int x, IntList a) {
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return searchRecursiveHelper(x, a, 0, a.getLength() - 1);
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}
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private static int searchRecursiveHelper(
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int x,
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IntList a,
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int low,
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int high
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) {
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if (low > high) {
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return low;
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}
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int mid = low + (high - low) / 2;
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if (a.get(mid) <= x) {
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return searchRecursiveHelper(x, a, low, mid - 1);
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} else {
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return searchRecursiveHelper(x, a, mid + 1, high);
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}
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}
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}
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