240507 수 이어 쓰기

public static void main(String[] args) throws IOException {
	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
	StringTokenizer st = new StringTokenizer(br.readLine());
	
	String num = st.nextToken();
	int len = num.length();
	int[] nums = new int[len];
	for(int i = 0; i < len; i++) {
		nums[i] = num.charAt(i) - '0';
	}
	
	int idx = 0;
	int n = 0;
	while(idx < len) {
		n++;
		int temp = n;
		int length = (int)(Math.log10(n) + 1);
		int[] arr = new int[length];
		for(int i = length - 1; i >= 0; i--) {
			arr[i] = temp % 10;
			temp /= 10;
		}
		for(int i = 0; i < length; i++) {
			if(nums[idx] == arr[i])
				idx++;
			if(idx >= len)
				break;
		}
	}
	bw.write(n + "");
	bw.close();
}

출처:https://www.acmicpc.net/problem/1515