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fishercoder1534fishercoder1534
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add a solution for 179
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-79
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‎src/main/java/com/fishercoder/solutions/_179.java

Lines changed: 80 additions & 79 deletions
Original file line numberDiff line numberDiff line change
@@ -1,89 +1,90 @@
11
package com.fishercoder.solutions;
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import java.util.Arrays;
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import java.util.Comparator;
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import java.util.*;
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/**
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* 179. Largest Number
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Given a list of non negative integers, arrange them such that they form the largest number.
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Example 1:
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Input: [10,2]
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Output: "210"
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Example 2:
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Input: [3,30,34,5,9]
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Output: "9534330"
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Note: The result may be very large, so you need to return a string instead of an integer.
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*/
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public class _179 {
246

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public static class Solution1 {
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public String largestNumber(int[] num) {
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if (num.length == 0) {
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return "";
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}
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if (num.length == 1) {
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return Integer.toString(num[0]);
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}
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String[] str = new String[num.length];
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for (int i = 0; i < num.length; i++) {
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str[i] = Integer.toString(num[i]);
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}
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Arrays.sort(str, new StringComparator());
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StringBuilder sb = new StringBuilder("");
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for (int i = num.length - 1; i >= 0; i--) {
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sb.append(str[i]);
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}
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if (sb.charAt(0) == '0') {
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return "0";
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}
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return sb.toString();
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}
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class StringComparator implements Comparator<String> {
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public int compare(String s1, String s2) {
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if (s1.length() == 0 && s2.length() == 0) {
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return 0;
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}
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if (s2.length() == 0) {
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return 1;
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}
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if (s1.length() == 0) {
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return -1;
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}
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for (int i = 0; i < s1.length() && i < s2.length(); i++) {
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if (s1.charAt(i) > s2.charAt(i)) {
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return 1;
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} else if (s1.charAt(i) < s2.charAt(i)) {
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return -1;
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}
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public static class Solution1 {
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public String largestNumber(int[] num) {
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if (num.length == 0) {
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return "";
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}
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if (num.length == 1) {
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return Integer.toString(num[0]);
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}
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String[] str = new String[num.length];
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for (int i = 0; i < num.length; i++) {
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str[i] = Integer.toString(num[i]);
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}
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Arrays.sort(str, new StringComparator());
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StringBuilder sb = new StringBuilder("");
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for (int i = num.length - 1; i >= 0; i--) {
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sb.append(str[i]);
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}
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if (sb.charAt(0) == '0') {
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return "0";
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}
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return sb.toString();
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}
66-
if (s1.length() == s2.length()) {
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return 0;
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class StringComparator implements Comparator<String> {
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public int compare(String s1, String s2) {
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if (s1.length() == 0 && s2.length() == 0) {
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return 0;
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}
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if (s2.length() == 0) {
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return 1;
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}
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if (s1.length() == 0) {
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return -1;
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}
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for (int i = 0; i < s1.length() && i < s2.length(); i++) {
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if (s1.charAt(i) > s2.charAt(i)) {
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return 1;
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} else if (s1.charAt(i) < s2.charAt(i)) {
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return -1;
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}
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}
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if (s1.length() == s2.length()) {
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return 0;
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}
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if (s1.length() > s2.length()) {
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if (s1.charAt(0) < s1.charAt(s2.length())) {
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return 1;
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} else if (s1.charAt(0) > s1.charAt(s2.length())) {
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return -1;
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} else {
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return compare(s1.substring(s2.length()), s2);
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}
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} else {
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if (s2.charAt(0) < s2.charAt(s1.length())) {
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return -1;
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} else if (s2.charAt(0) > s2.charAt(s1.length())) {
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return 1;
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} else {
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return compare(s1, s2.substring(s1.length()));
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}
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}
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}
6869
}
69-
if (s1.length() > s2.length()) {
70-
if (s1.charAt(0) < s1.charAt(s2.length())) {
71-
return 1;
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} else if (s1.charAt(0) > s1.charAt(s2.length())) {
73-
return -1;
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} else {
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return compare(s1.substring(s2.length()), s2);
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}
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} else {
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if (s2.charAt(0) < s2.charAt(s1.length())) {
79-
return -1;
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} else if (s2.charAt(0) > s2.charAt(s1.length())) {
81-
return 1;
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} else {
83-
return compare(s1, s2.substring(s1.length()));
84-
}
70+
}
71+
72+
public static class Solution2 {
73+
/**
74+
* My completely original solution on 11/29/2021:
75+
* we'll just sort these numbers as if they are strings.
76+
*/
77+
public String largestNumber(int[] nums) {
78+
List<String> strings = new ArrayList<>();
79+
for (int num : nums) {
80+
strings.add(Integer.toString(num));
81+
}
82+
Collections.sort(strings, (a, b) -> (b + a).compareToIgnoreCase(a + b));
83+
StringBuilder sb = new StringBuilder();
84+
for (int i = 0; i < strings.size(); i++) {
85+
sb.append(strings.get(i));
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}
87+
return sb.charAt(0) == '0' ? "0" : sb.toString();
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}
86-
}
8789
}
88-
}
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}

‎src/test/java/com/fishercoder/_179Test.java

Lines changed: 53 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,53 @@
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package com.fishercoder;
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import com.fishercoder.solutions._179;
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import org.junit.BeforeClass;
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import org.junit.Test;
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import static org.junit.Assert.assertEquals;
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9+
public class _179Test {
10+
private static _179.Solution1 solution1;
11+
private static _179.Solution2 solution2;
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private static int[] nums;
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private static String expected;
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15+
@BeforeClass
16+
public static void setup() {
17+
solution1 = new _179.Solution1();
18+
solution2 = new _179.Solution2();
19+
}
20+
21+
@Test
22+
public void test1() {
23+
nums = new int[]{34323, 3432};
24+
expected = "343234323";
25+
assertEquals(expected, solution1.largestNumber(nums));
26+
assertEquals(expected, solution2.largestNumber(nums));
27+
}
28+
29+
@Test
30+
public void test2() {
31+
nums = new int[]{111311, 1113};
32+
expected = "1113111311";
33+
assertEquals(expected, solution1.largestNumber(nums));
34+
assertEquals(expected, solution2.largestNumber(nums));
35+
}
36+
37+
@Test
38+
public void test3() {
39+
nums = new int[]{3, 30, 34, 5, 9};
40+
expected = "9534330";
41+
assertEquals(expected, solution1.largestNumber(nums));
42+
assertEquals(expected, solution2.largestNumber(nums));
43+
}
44+
45+
@Test
46+
public void test4() {
47+
nums = new int[]{0, 0};
48+
expected = "0";
49+
assertEquals(expected, solution1.largestNumber(nums));
50+
assertEquals(expected, solution2.largestNumber(nums));
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}
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53+
}

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