package class001;

import java.util.Arrays;

public class Code02_ContainAllCharExactly {

	public static int containExactly1(String s, String a) {
		if (s == null || a == null || s.length() < a.length()) {
			return -1;
		}
		char[] aim = a.toCharArray();
		Arrays.sort(aim);
		String aimSort = String.valueOf(aim);
		for (int L = 0; L < s.length(); L++) {
			for (int R = L; R < s.length(); R++) {
				char[] cur = s.substring(L, R + 1).toCharArray();
				Arrays.sort(cur);
				String curSort = String.valueOf(cur);
				if (curSort.equals(aimSort)) {
					return L;
				}
			}
		}
		return -1;
	}

	public static int containExactly2(String s, String a) {
		if (s == null || a == null || s.length() < a.length()) {
			return -1;
		}
		char[] str = s.toCharArray();
		char[] aim = a.toCharArray();
		for (int L = 0; L <= str.length - aim.length; L++) {
			if (isCountEqual(str, L, aim)) {
				return L;
			}
		}
		return -1;
	}

	public static boolean isCountEqual(char[] str, int L, char[] aim) {
		int[] count = new int[256];
		for (int i = 0; i < aim.length; i++) {
			count[aim[i]]++;
		}
		for (int i = 0; i < aim.length; i++) {
			if (count[str[L + i]]-- == 0) {
				return false;
			}
		}
		return true;
	}

	public static int containExactly3(String s, String a) {
		if (s == null || a == null || s.length() < a.length()) {
			return -1;
		}
		char[] aim = a.toCharArray();
		int[] count = new int[256];
		for (int i = 0; i < aim.length; i++) {
			count[aim[i]]++;
		}
		int M = aim.length;
		char[] str = s.toCharArray();
		int inValidTimes = 0;
		int R = 0;
		for (; R < M; R++) {
			if (count[str[R]]-- <= 0) {
				inValidTimes++;
			}
		}
		for (; R < str.length; R++) {
			if (inValidTimes == 0) {
				return R - M;
			}
			if (count[str[R]]-- <= 0) {
				inValidTimes++;
			}
			if (count[str[R - M]]++ < 0) {
				inValidTimes--;
			}
		}
		return inValidTimes == 0 ? R - M : -1;
	}

	// for test
	public static String getRandomString(int possibilities, int maxSize) {
		char[] ans = new char[(int) (Math.random() * maxSize) + 1];
		for (int i = 0; i < ans.length; i++) {
			ans[i] = (char) ((int) (Math.random() * possibilities) + 'a');
		}
		return String.valueOf(ans);
	}

	public static void main(String[] args) {
		int possibilities = 5;
		int strMaxSize = 20;
		int aimMaxSize = 5;
		int testTimes = 500000;
		System.out.println("test begin, test time : " + testTimes);
		for (int i = 0; i < testTimes; i++) {
			String str = getRandomString(possibilities, strMaxSize);
			String aim = getRandomString(possibilities, aimMaxSize);
			int ans1 = containExactly1(str, aim);
			int ans2 = containExactly2(str, aim);
			int ans3 = containExactly3(str, aim);
			if (ans1 != ans2 || ans2 != ans3) {
				System.out.println("Oops!");
			}
		}
		System.out.println("test finish");

	}

}