poj 1065 Wooden Sticks 2011/08/28

Javaです。POJです。 1065 -- Wooden Sticks
これも自力でないです。
いろいろ参考にしましたが、よく理解できてないです。
PKU 1065 Wooden Sticks - 敗戦記
 

package p1065_not_completed; import java.io.IOException; import java.util.Scanner; public class Main { static boolean debug = false; static class Pair { int w; int l; boolean use = false; public Pair(int l, int w) { this.w = w; this.l = l; } public String toString() { return "l:[" + l + "] w:[" + w + "] use:[" + use + "]"; } } public static void main(String[] args) throws IOException { Scanner scanner = new Scanner(System.in); int t = scanner.nextInt(); for (int i = 0; i < t; i++) { int setupTime = 0; int n = scanner.nextInt(); Pair[] pairs = new Pair[n]; for (int j = 0; j < n; j++) { int l = scanner.nextInt(); int w = scanner.nextInt(); Pair pair = new Pair(l, w); pairs[j] = pair; } sort(pairs); print(pairs); setupTime = count(pairs); System.out.println(setupTime); } } static void print(Pair[] pairs) { if (!debug) return; for (Pair pair : pairs) { System.err.println(pair); } System.err.println(); } static void sort(Pair[] pairs) { for (int i = 0; i < pairs.length; i++) { print(pairs); for (int k = i + 1; k < pairs.length; k++) { if (pairs[i].l < pairs[k].l) { Pair pair = pairs[i]; pairs[i] = pairs[k]; pairs[k] = pair; } } } } static int count(Pair[] pairs) { int c = 0; for (int i = 0; i < pairs.length; i++) { Pair p1 = pairs[i]; if (p1.use) continue; for (int j = i + 1; j < pairs.length; j++) { Pair p2 = pairs[j]; if (p2.use) continue; if ((p2.l <= p1.l && p2.w <= p1.w)) { p2.use = true; p1 = p2; } } c++; } return c; } }