LeetCode 788. Rotated Digits - Weekly Contest 73

https://leetcode.com/contest/weekly-contest-73/problems/rotated-digits/

Quite Straight Forward,
in case of 25, 69 they change to something beautiful.
in case of 0, 1, 8, they just don't mean anything,
in case of the 3, 4, 7 they are pretty much deal breaker.

the conditions are messy so I speed them up with an array.

	class Solution {
	public int rotatedDigits(int N) {
	// filter abnormal cases
	int count = 0;
	this.N = N;
	for (int i = 1; i <= N; i++) {
	if (isGood(i)) {
	count++;
	}
	}
	// return the final result
	return count;
	}
	int N;
	int[] change = new int[]{0, 0, 5, -1, -1, 2, 9, -1, 0, 6};
	private boolean isGood(int i) {
	boolean isChange = false;
	while (i > 0) {
	int digit = i % 10;
	i /= 10;
	if (change[digit] == -1) {
	return false;
	} else if (change[digit] != 0) {
	isChange = true;
	}
	}
	return isChange;
	}
	}

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