Problem:
Score: 300 points

Problem Statement

In Republic of Atcoder, there are N prefectures, and a total of M cities that belong to those prefectures.

City i is established in year Y_i and belongs to Prefecture P_i.

You can assume that there are no multiple cities that are established in the same year.

It is decided to allocate a 12-digit ID number to each city.

If City i is the x-th established city among the cities that belong to Prefecture i, the first six digits of the ID number of City i is P_i, and the last six digits of the ID number is x.

Here, if P_i or x (or both) has less than six digits, zeros are added to the left until it has six digits.

Find the ID numbers for all the cities.

Note that there can be a prefecture with no cities.

Constraints

1 \leq N \leq 10^5

1 \leq M \leq 10^5

1 \leq P_i \leq N

1 \leq Y_i \leq 10^9

Y_i are all different.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N M
P_1 Y_1
:
P_M Y_M

Output

Print the ID numbers for all the cities, in ascending order of indices (City 1, City 2, ...).

Sample Input 1

2 3
1 32
2 63
1 12

Sample Output 1

000001000002
000002000001
000001000001

As City 1 is the second established city among the cities that belong to Prefecture 1, its ID number is 000001000002.

As City 2 is the first established city among the cities that belong to Prefecture 2, its ID number is 000002000001.

As City 3 is the first established city among the cities that belong to Prefecture 1, its ID number is 000001000001.

Sample Input 2

2 3
2 55
2 77
2 99

Sample Output 2

000002000001
000002000002
000002000003

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)


import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Arrays;

public class Main {
	private static boolean ispf = false;

	public static void main(String[] args) throws Exception {

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] systemInLine = br.readLine().split(" ");
		int provinceCount = Integer.parseInt(systemInLine[0]);
		int cityCount = Integer.parseInt(systemInLine[1]);
		pf("辖区总数:" + provinceCount + " 城市总数:" + cityCount);

		/**
		 * 所有的城市
		 */

		// 城市数组，0：省份，1：年份，2：输入顺序号，4：年份序号
		int[][] proviceCityArray = new int[cityCount][4];

		for (int i = 0; i < cityCount; i++) {
			systemInLine = br.readLine().split(" ");
			int provinceIndex = Integer.parseInt(systemInLine[0]);
			int cityCreateYear = Integer.parseInt(systemInLine[1]);
			proviceCityArray[i][0] = provinceIndex;
			proviceCityArray[i][1] = cityCreateYear;
			proviceCityArray[i][2] = i + 1;
		}
		br.close();

		/**
		 * 这次排序后辖区和年份已经排序了
		 */

		Arrays.sort(proviceCityArray, (o1, o2) -> (o1[0] == o2[0]) ? (o1[1] - o2[1]) : (o1[0] - o2[0]));

		for (int i = 0; i < proviceCityArray.length; i++) {
			if (i == 0) {
				proviceCityArray[i][3] = 1;
			} else {
				if ((proviceCityArray[i][0] == proviceCityArray[i - 1][0])) {// 于上一次比较
					proviceCityArray[i][3] = proviceCityArray[i - 1][3] + 1;
				} else {
					proviceCityArray[i][3] = 1;
				}
			}
		}

		/**
		 * 再次排序拍会回来
		 */
		Arrays.sort(proviceCityArray, (o1, o2) -> o1[2] - o2[2]);
		String[] padding = new String[] { "", "0", "00", "000", "0000", "00000" };
		for (int i = 0; i < proviceCityArray.length; i++) {
			// System.out.println(String.format("%06d",
			// proviceCityArray[i][0])+String.format("%06d", proviceCityArray[i][3]));
			System.out.println(padding[getPadingIndex(proviceCityArray[i][0])] + proviceCityArray[i][0]
					+ padding[getPadingIndex(proviceCityArray[i][3])] + proviceCityArray[i][3]);
		}

	}

	public static void pf(String s) {
		if (ispf) {
			System.out.println(s);
		}
	}

	private static int getPadingIndex(int n) {
	        if (n < 10) {
	        	return 5;
        	}else if (n < 100) {
        		return 4;
        	}else if (n < 1000) {
        		return 3;
        	}else if (n < 10000) {
        		return 2;
        	}else if (n < 100000) { 
        		return 1;
        	}else {
        		return 0;
        	}
	    }
}